David Howells says:

====================
rxrpc: Fixes for AF_RXRPC

Here are a couple of fixes for the AF_RXRPC changes[1] in net-next.

 (1) Fix a runtime warning introduced by a patch that changed how
     page_frag_alloc_align() works.

 (2) Fix an is-NULL vs IS_ERR error handling bug.

The patches are tagged here:

	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git tags/rxrpc-iothread-20240312

And can be found on this branch:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-iothread

Link: https://lore.kernel.org/r/20240306000655.1100294-1-dhowells@redhat.com/ [1]
====================

Link: https://lore.kernel.org/r/20240312233723.2984928-1-dhowells@redhat.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rxrpc_alloc_*_txbuf() and ->alloc_txbuf() return NULL to indicate no
memory, but rxrpc_send_data() uses IS_ERR().

Fix rxrpc_send_data() to check for NULL only and set -ENOMEM if it sees
that.

Fixes: 49489bb0 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Commit 411c5f36 ("mm/page_alloc: modify page_frag_alloc_align() to
accept align as an argument") changed the way page_frag_alloc_align()
worked, but it didn't fix AF_RXRPC as that use of that allocator function
hadn't been merged yet at the time.  Now, when the AFS filesystem is used,
this results in:

  WARNING: CPU: 4 PID: 379 at include/linux/gfp.h:323 rxrpc_alloc_data_txbuf+0x9d/0x2b0 [rxrpc]

Fix this by using __page_frag_alloc_align() instead.

Note that it might be better to use an order-based alignment rather than a
mask-based alignment.

Fixes: 49489bb0 ("rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags")
Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
cc: Yunsheng Lin <linyunsheng@huawei.com>
cc: Alexander Duyck <alexander.duyck@gmail.com>
cc: Michael S. Tsirkin <mst@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

KMSAN reported the following uninit-value access issue [1]:

=====================================================
BUG: KMSAN: uninit-value in hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246
 hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246
 fill_frame_info net/hsr/hsr_forward.c:577 [inline]
 hsr_forward_skb+0xe12/0x30e0 net/hsr/hsr_forward.c:615
 hsr_dev_xmit+0x1a1/0x270 net/hsr/hsr_device.c:223
 __netdev_start_xmit include/linux/netdevice.h:4940 [inline]
 netdev_start_xmit include/linux/netdevice.h:4954 [inline]
 xmit_one net/core/dev.c:3548 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564
 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349
 dev_queue_xmit include/linux/netdevice.h:3134 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x735/0xa10 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
 slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
 __alloc_skb+0x318/0x740 net/core/skbuff.c:651
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787
 packet_alloc_skb net/packet/af_packet.c:2936 [inline]
 packet_snd net/packet/af_packet.c:3030 [inline]
 packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x735/0xa10 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 1 PID: 5033 Comm: syz-executor334 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================

If the packet type ID field in the Ethernet header is either ETH_P_PRP or
ETH_P_HSR, but it is not followed by an HSR tag, hsr_get_skb_sequence_nr()
reads an invalid value as a sequence number. This causes the above issue.

This patch fixes the issue by returning NULL if the Ethernet header is not
followed by an HSR tag.

Fixes: f266a683 ("net/hsr: Better frame dispatch")
Reported-and-tested-by:  <syzbot+2ef3a8ce8e91b5a50098@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=2ef3a8ce8e91b5a50098

 [1]
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Link: https://lore.kernel.org/r/20240312152719.724530-1-syoshida@redhat.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Use rbi->len instead of rcd->len for non-dataring packet.

Found issue:
  XDP_WARN: xdp_update_frame_from_buff(line:278): Driver BUG: missing reserved tailroom
  WARNING: CPU: 0 PID: 0 at net/core/xdp.c:586 xdp_warn+0xf/0x20
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W  O       6.5.1 #1
  RIP: 0010:xdp_warn+0xf/0x20
  ...
  ? xdp_warn+0xf/0x20
  xdp_do_redirect+0x15f/0x1c0
  vmxnet3_run_xdp+0x17a/0x400 [vmxnet3]
  vmxnet3_process_xdp+0xe4/0x760 [vmxnet3]
  ? vmxnet3_tq_tx_complete.isra.0+0x21e/0x2c0 [vmxnet3]
  vmxnet3_rq_rx_complete+0x7ad/0x1120 [vmxnet3]
  vmxnet3_poll_rx_only+0x2d/0xa0 [vmxnet3]
  __napi_poll+0x20/0x180
  net_rx_action+0x177/0x390

Reported-by: Martin Zaharinov <micron10@gmail.com>
Tested-by: Martin Zaharinov <micron10@gmail.com>
Link: https://lore.kernel.org/netdev/74BF3CC8-2A3A-44FF-98C2-1E20F110A92E@gmail.com/


Fixes: 54f00cce ("vmxnet3: Add XDP support.")
Signed-off-by: William Tu <witu@nvidia.com>
Link: https://lore.kernel.org/r/20240309183147.28222-1-witu@nvidia.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>

syzbot reported a warning in sk_nulls_del_node_init_rcu().

The commit 66b60b0c ("dccp/tcp: Unhash sk from ehash for tb2 alloc
failure after check_estalblished().") tried to fix an issue that an
unconnected socket occupies an ehash entry when bhash2 allocation fails.

In such a case, we need to revert changes done by check_established(),
which does not hold refcnt when inserting socket into ehash.

So, to revert the change, we need to __sk_nulls_add_node_rcu() instead
of sk_nulls_add_node_rcu().

Otherwise, sock_put() will cause refcnt underflow and leak the socket.

[0]:
WARNING: CPU: 0 PID: 23948 at include/net/sock.h:799 sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799
Modules linked in:
CPU: 0 PID: 23948 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00159-gc055fc00c07b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799
Code: e8 7f 71 c6 f7 83 fb 02 7c 25 e8 35 6d c6 f7 4d 85 f6 0f 95 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 1b 6d c6 f7 90 <0f> 0b 90 eb b2 e8 10 6d c6 f7 4c 89 e7 be 04 00 00 00 e8 63 e7 d2
RSP: 0018:ffffc900032d7848 EFLAGS: 00010246
RAX: ffffffff89cd0035 RBX: 0000000000000001 RCX: 0000000000040000
RDX: ffffc90004de1000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 1ffff1100439ac26 R08: ffffffff89ccffe3 R09: 1ffff1100439ac28
R10: dffffc0000000000 R11: ffffed100439ac29 R12: ffff888021cd6140
R13: dffffc0000000000 R14: ffff88802a9bf5c0 R15: ffff888021cd6130
FS:  00007f3b823f16c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b823f0ff8 CR3: 000000004674a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __inet_hash_connect+0x140f/0x20b0 net/ipv4/inet_hashtables.c:1139
 dccp_v6_connect+0xcb9/0x1480 net/dccp/ipv6.c:956
 __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:678
 inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:749
 __sys_connect_file net/socket.c:2048 [inline]
 __sys_connect+0x2df/0x310 net/socket.c:2065
 __do_sys_connect net/socket.c:2075 [inline]
 __se_sys_connect net/socket.c:2072 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2072
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f3b8167dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b823f10c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f3b817abf80 RCX: 00007f3b8167dda9
RDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00007f3b823f1120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 000000000000000b R14: 00007f3b817abf80 R15: 00007ffd3beb57b8
 </TASK>

Reported-by:  <syzbot+12c506c1aae251e70449@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=12c506c1aae251e70449


Fixes: 66b60b0c ("dccp/tcp: Unhash sk from ehash for tb2 alloc failure after check_estalblished().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240308201623.65448-1-kuniyu@amazon.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Commit 870c7ad4 ("devlink: protect devlink->dev by the instance
lock") added devlink instance locking inside a loop that iterates over
all the registered devlink instances on the machine in the pre-doit
phase. This can lead to serialization of devlink commands over
different devlink instances.

For example: While the first devlink instance is executing firmware
flash, all commands to other devlink instances on the machine are
forced to wait until the first devlink finishes.

Therefore, in the pre-doit phase, take the devlink instance lock only
for the devlink instance the command is targeting. Devlink layer is
taking a reference on the devlink instance, ensuring the devlink->dev
pointer is valid. This reference taking was introduced by commit
a3806872 ("devlink: take device reference for devlink object").
Without this commit, it would not be safe to access devlink->dev
lockless.

Fixes: 870c7ad4 ("devlink: protect devlink->dev by the instance lock")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

taprio_parse_tc_entry() is not correctly checking
TCA_TAPRIO_TC_ENTRY_INDEX attribute:

	int tc; // Signed value

	tc = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_INDEX]);
	if (tc >= TC_QOPT_MAX_QUEUE) {
		NL_SET_ERR_MSG_MOD(extack, "TC entry index out of range");
		return -ERANGE;
	}

syzbot reported that it could fed arbitary negative values:

UBSAN: shift-out-of-bounds in net/sched/sch_taprio.c:1722:18
shift exponent -2147418108 is negative
CPU: 0 PID: 5066 Comm: syz-executor367 Not tainted 6.8.0-rc7-syzkaller-00136-gc8a5c731fd12 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
  ubsan_epilogue lib/ubsan.c:217 [inline]
  __ubsan_handle_shift_out_of_bounds+0x3c7/0x420 lib/ubsan.c:386
  taprio_parse_tc_entry net/sched/sch_taprio.c:1722 [inline]
  taprio_parse_tc_entries net/sched/sch_taprio.c:1768 [inline]
  taprio_change+0xb87/0x57d0 net/sched/sch_taprio.c:1877
  taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2134
  qdisc_create+0x9d4/0x1190 net/sched/sch_api.c:1355
  tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1776
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6617
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f1b2dea3759
Code: 48 83 c4 28 c3 e8 d7 19 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd4de452f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1b2def0390 RCX: 00007f1b2dea3759
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000555500000000 R09: 0000555500000000
R10: 0000555500000000 R11: 0000000000000246 R12: 00007ffd4de45340
R13: 00007ffd4de45310 R14: 0000000000000001 R15: 00007ffd4de45340

Fixes: a54fc09e ("net/sched: taprio: allow user input of per-tc max SDU")
Reported-and-tested-by:  <syzbot+a340daa06412d6028918@syzkaller.appspotmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use wake_up API instead of wake_up_interruptible, since
wait_event_timeout API is used for waiting on command completion.

Fixes: 1463f382 ("octeontx2-af: Add support for CGX link management")
Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

smp_call_function always runs its callback in hard IRQ context, even on
PREEMPT_RT, where spinlocks can sleep. So we need to use a raw spinlock
for cgr_lock to ensure we aren't waiting on a sleeping task.

Although this bug has existed for a while, it was not apparent until
commit ef2a8d54 ("net: dpaa: Adjust queue depth on rate change")
which invokes smp_call_function_single via qman_update_cgr_safe every
time a link goes up or down.

Fixes: 96f413f4 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()")
CC: stable@vger.kernel.org
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Closes: https://lore.kernel.org/all/20230323153935.nofnjucqjqnz34ej@skbuf/


Reported-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Closes: https://lore.kernel.org/linux-arm-kernel/87wmsyvclu.fsf@pengutronix.de/


Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

smp_call_function_single disables IRQs when executing the callback. To
prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere.
This is already done by qman_update_cgr and qman_delete_cgr; fix the
other lockers.

Fixes: 96f413f4 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()")
CC: stable@vger.kernel.org
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kuniyuki Iwashima says:

====================
tcp/rds: Fix use-after-free around kernel TCP reqsk.

syzkaller reported an warning of netns ref tracker for RDS TCP listener,
which commit 740ea3c4 ("tcp: Clean up kernel listener's reqsk in
inet_twsk_purge()") fixed for per-netns ehash.

This series fixes the bug in the partial fix and fixes the reported bug
in the global ehash.

v4: https://lore.kernel.org/netdev/20240307232151.55963-1-kuniyu@amazon.com/
v3: https://lore.kernel.org/netdev/20240307224423.53315-1-kuniyu@amazon.com/
v2: https://lore.kernel.org/netdev/20240227011041.97375-1-kuniyu@amazon.com/
v1: https://lore.kernel.org/netdev/20240223172448.94084-1-kuniyu@amazon.com/
====================

Link: https://lore.kernel.org/r/20240308200122.64357-1-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

syzkaller reported a warning of netns tracker [0] followed by KASAN
splat [1] and another ref tracker warning [1].

syzkaller could not find a repro, but in the log, the only suspicious
sequence was as follows:

  18:26:22 executing program 1:
  r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
  ...
  connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)

The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.

So, the scenario would be:

  1. unshare(CLONE_NEWNET) creates a per netns tcp listener in
      rds_tcp_listen_init().
  2. syz-executor connect()s to it and creates a reqsk.
  3. syz-executor exit()s immediately.
  4. netns is dismantled.  [0]
  5. reqsk timer is fired, and UAF happens while freeing reqsk.  [1]
  6. listener is freed after RCU grace period.  [2]

Basically, reqsk assumes that the listener guarantees netns safety
until all reqsk timers are expired by holding the listener's refcount.
However, this was not the case for kernel sockets.

Commit 740ea3c4 ("tcp: Clean up kernel listener's reqsk in
inet_twsk_purge()") fixed this issue only for per-netns ehash.

Let's apply the same fix for the global ehash.

[0]:
ref_tracker: net notrefcnt@0000000065449cc3 has 1/1 users at
     sk_alloc (./include/net/net_namespace.h:337 net/core/sock.c:2146)
     inet6_create (net/ipv6/af_inet6.c:192 net/ipv6/af_inet6.c:119)
     __sock_create (net/socket.c:1572)
     rds_tcp_listen_init (net/rds/tcp_listen.c:279)
     rds_tcp_init_net (net/rds/tcp.c:577)
     ops_init (net/core/net_namespace.c:137)
     setup_net (net/core/net_namespace.c:340)
     copy_net_ns (net/core/net_namespace.c:497)
     create_new_namespaces (kernel/nsproxy.c:110)
     unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
     ksys_unshare (kernel/fork.c:3429)
     __x64_sys_unshare (kernel/fork.c:3496)
     do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
     entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
...
WARNING: CPU: 0 PID: 27 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179)

[1]:
BUG: KASAN: slab-use-after-free in inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
Read of size 8 at addr ffff88801b370400 by task swapper/0/0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
 print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
 kasan_report (mm/kasan/report.c:603)
 inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
 reqsk_timer_handler (net/ipv4/inet_connection_sock.c:979 net/ipv4/inet_connection_sock.c:1092)
 call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701)
 __run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2038)
 run_timer_softirq (kernel/time/timer.c:2053)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
 irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
 sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
 </IRQ>

Allocated by task 258 on cpu 0 at 83.612050s:
 kasan_save_stack (mm/kasan/common.c:48)
 kasan_save_track (mm/kasan/common.c:68)
 __kasan_slab_alloc (mm/kasan/common.c:343)
 kmem_cache_alloc (mm/slub.c:3813 mm/slub.c:3860 mm/slub.c:3867)
 copy_net_ns (./include/linux/slab.h:701 net/core/net_namespace.c:421 net/core/net_namespace.c:480)
 create_new_namespaces (kernel/nsproxy.c:110)
 unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
 ksys_unshare (kernel/fork.c:3429)
 __x64_sys_unshare (kernel/fork.c:3496)
 do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)

Freed by task 27 on cpu 0 at 329.158864s:
 kasan_save_stack (mm/kasan/common.c:48)
 kasan_save_track (mm/kasan/common.c:68)
 kasan_save_free_info (mm/kasan/generic.c:643)
 __kasan_slab_free (mm/kasan/common.c:265)
 kmem_cache_free (mm/slub.c:4299 mm/slub.c:4363)
 cleanup_net (net/core/net_namespace.c:456 net/core/net_namespace.c:446 net/core/net_namespace.c:639)
 process_one_work (kernel/workqueue.c:2638)
 worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787)
 kthread (kernel/kthread.c:388)
 ret_from_fork (arch/x86/kernel/process.c:153)
 ret_from_fork_asm (arch/x86/entry/entry_64.S:250)

The buggy address belongs to the object at ffff88801b370000
 which belongs to the cache net_namespace of size 4352
The buggy address is located 1024 bytes inside of
 freed 4352-byte region [ffff88801b370000, ffff88801b371100)

[2]:
WARNING: CPU: 0 PID: 95 at lib/ref_tracker.c:228 ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
Modules linked in:
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:ref_tracker_free (lib/ref_tracker.c:228 (discriminator 1))
...
Call Trace:
<IRQ>
 __sk_destruct (./include/net/net_namespace.h:353 net/core/sock.c:2204)
 rcu_core (./arch/x86/include/asm/preempt.h:26 kernel/rcu/tree.c:2165 kernel/rcu/tree.c:2433)
 __do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
 irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
 sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
</IRQ>

Reported-by: syzkaller <syzkaller@googlegroups.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: 467fa153 ("RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240308200122.64357-3-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inet_twsk_purge() uses rcu to find TIME_WAIT and NEW_SYN_RECV
objects to purge.

These objects use SLAB_TYPESAFE_BY_RCU semantic and need special
care. We need to use refcount_inc_not_zero(&sk->sk_refcnt).

Reuse the existing correct logic I wrote for TIME_WAIT,
because both structures have common locations for
sk_state, sk_family, and netns pointer.

If after the refcount_inc_not_zero() the object fields longer match
the keys, use sock_gen_put(sk) to release the refcount.

Then we can call inet_twsk_deschedule_put() for TIME_WAIT,
inet_csk_reqsk_queue_drop_and_put() for NEW_SYN_RECV sockets,
with BH disabled.

Then we need to restart the loop because we had drop rcu_read_lock().

Fixes: 740ea3c4 ("tcp: Clean up kernel listener's reqsk in inet_twsk_purge()")
Link: https://lore.kernel.org/netdev/CANn89iLvFuuihCtt9PME2uS1WJATnf5fKjDToa1WzVnRzHnPfg@mail.gmail.com/T/#u


Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240308200122.64357-2-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Large effort by Eric to lower rtnl_lock pressure and remove locks:

      - Make commonly used parts of rtnetlink (address, route dumps
        etc) lockless, protected by RCU instead of rtnl_lock.

      - Add a netns exit callback which already holds rtnl_lock,
        allowing netns exit to take rtnl_lock once in the core instead
        of once for each driver / callback.

      - Remove locks / serialization in the socket diag interface.

      - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

      - Remove the dev_base_lock, depend on RCU where necessary.

   - Support busy polling on a per-epoll context basis. Poll length and
     budget parameters can be set independently of system defaults.

   - Introduce struct net_hotdata, to make sure read-mostly global
     config variables fit in as few cache lines as possible.

   - Add optional per-nexthop statistics to ease monitoring / debug of
     ECMP imbalance problems.

   - Support TCP_NOTSENT_LOWAT in MPTCP.

   - Ensure that IPv6 temporary addresses' preferred lifetimes are long
     enough, compared to other configured lifetimes, and at least 2 sec.

   - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

   - Add support for the independent control state machine for bonding
     per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
     control state machine.

   - Add "network ID" to MCTP socket APIs to support hosts with multiple
     disjoint MCTP networks.

   - Re-use the mono_delivery_time skbuff bit for packets which user
     space wants to be sent at a specified time. Maintain the timing
     information while traversing veth links, bridge etc.

   - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

   - Simplify many places iterating over netdevs by using an xarray
     instead of a hash table walk (hash table remains in place, for use
     on fastpaths).

   - Speed up scanning for expired routes by keeping a dedicated list.

   - Speed up "generic" XDP by trying harder to avoid large allocations.

   - Support attaching arbitrary metadata to netconsole messages.

  Things we sprinkled into general kernel code:

   - Enforce VM_IOREMAP flag and range in ioremap_page_range and
     introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
     bpf_arena).

   - Rework selftest harness to enable the use of the full range of ksft
     exit code (pass, fail, skip, xfail, xpass).

  Netfilter:

   - Allow userspace to define a table that is exclusively owned by a
     daemon (via netlink socket aliveness) without auto-removing this
     table when the userspace program exits. Such table gets marked as
     orphaned and a restarting management daemon can re-attach/regain
     ownership.

   - Speed up element insertions to nftables' concatenated-ranges set
     type. Compact a few related data structures.

  BPF:

   - Add BPF token support for delegating a subset of BPF subsystem
     functionality from privileged system-wide daemons such as systemd
     through special mount options for userns-bound BPF fs to a trusted
     & unprivileged application.

   - Introduce bpf_arena which is sparse shared memory region between
     BPF program and user space where structures inside the arena can
     have pointers to other areas of the arena, and pointers work
     seamlessly for both user-space programs and BPF programs.

   - Introduce may_goto instruction that is a contract between the
     verifier and the program. The verifier allows the program to loop
     assuming it's behaving well, but reserves the right to terminate
     it.

   - Extend the BPF verifier to enable static subprog calls in spin lock
     critical sections.

   - Support registration of struct_ops types from modules which helps
     projects like fuse-bpf that seeks to implement a new struct_ops
     type.

   - Add support for retrieval of cookies for perf/kprobe multi links.

   - Support arbitrary TCP SYN cookie generation / validation in the TC
     layer with BPF to allow creating SYN flood handling in BPF
     firewalls.

   - Add code generation to inline the bpf_kptr_xchg() helper which
     improves performance when stashing/popping the allocated BPF
     objects.

  Wireless:

   - Add SPP (signaling and payload protected) AMSDU support.

   - Support wider bandwidth OFDMA, as required for EHT operation.

  Driver API:

   - Major overhaul of the Energy Efficient Ethernet internals to
     support new link modes (2.5GE, 5GE), share more code between
     drivers (especially those using phylib), and encourage more
     uniform behavior. Convert and clean up drivers.

   - Define an API for querying per netdev queue statistics from
     drivers.

   - IPSec: account in global stats for fully offloaded sessions.

   - Create a concept of Ethernet PHY Packages at the Device Tree level,
     to allow parameterizing the existing PHY package code.

   - Enable Rx hashing (RSS) on GTP protocol fields.

  Misc:

   - Improvements and refactoring all over networking selftests.

   - Create uniform module aliases for TC classifiers, actions, and
     packet schedulers to simplify creating modprobe policies.

   - Address all missing MODULE_DESCRIPTION() warnings in networking.

   - Extend the Netlink descriptions in YAML to cover message
     encapsulation or "Netlink polymorphism", where interpretation of
     nested attributes depends on link type, classifier type or some
     other "class type".

  Drivers:

   - Ethernet high-speed NICs:
      - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
      - Intel (100G, ice, idpf):
         - support E825-C devices
      - nVidia/Mellanox:
         - support devices with one port and multiple PCIe links
      - Broadcom (bnxt):
         - support n-tuple filters
         - support configuring the RSS key
      - Wangxun (ngbe/txgbe):
         - implement irq_domain for TXGBE's sub-interrupts
      - Pensando/AMD:
         - support XDP
         - optimize queue submission and wakeup handling (+17% bps)
         - optimize struct layout, saving 28% of memory on queues

   - Ethernet NICs embedded and virtual:
      - Google cloud vNIC:
         - refactor driver to perform memory allocations for new queue
           config before stopping and freeing the old queue memory
      - Synopsys (stmmac):
         - obey queueMaxSDU and implement counters required by 802.1Qbv
      - Renesas (ravb):
         - support packet checksum offload
         - suspend to RAM and runtime PM support

   - Ethernet switches:
      - nVidia/Mellanox:
         - support for nexthop group statistics
      - Microchip:
         - ksz8: implement PHY loopback
         - add support for KSZ8567, a 7-port 10/100Mbps switch

   - PTP:
      - New driver for RENESAS FemtoClock3 Wireless clock generator.
      - Support OCP PTP cards designed and built by Adva.

   - CAN:
      - Support recvmsg() flags for own, local and remote traffic on CAN
        BCM sockets.
      - Support for esd GmbH PCIe/402 CAN device family.
      - m_can:
         - Rx/Tx submission coalescing
         - wake on frame Rx

   - WiFi:
      - Intel (iwlwifi):
         - enable signaling and payload protected A-MSDUs
         - support wider-bandwidth OFDMA
         - support for new devices
         - bump FW API to 89 for AX devices; 90 for BZ/SC devices
      - MediaTek (mt76):
         - mt7915: newer ADIE version support
         - mt7925: radio temperature sensor support
      - Qualcomm (ath11k):
         - support 6 GHz station power modes: Low Power Indoor (LPI),
           Standard Power) SP and Very Low Power (VLP)
         - QCA6390 & WCN6855: support 2 concurrent station interfaces
         - QCA2066 support
      - Qualcomm (ath12k):
         - refactoring in preparation for Multi-Link Operation (MLO)
           support
         - 1024 Block Ack window size support
         - firmware-2.bin support
         - support having multiple identical PCI devices (firmware needs
           to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
         - QCN9274: support split-PHY devices
         - WCN7850: enable Power Save Mode in station mode
         - WCN7850: P2P support
      - RealTek:
         - rtw88: support for more rtw8811cu and rtw8821cu devices
         - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
         - rtlwifi: speed up USB firmware initialization
         - rtwl8xxxu:
             - RTL8188F: concurrent interface support
             - Channel Switch Announcement (CSA) support in AP mode
      - Broadcom (brcmfmac):
         - per-vendor feature support
         - per-vendor SAE password setup
         - DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
  nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
  nexthop: Fix out-of-bounds access during attribute validation
  nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
  nexthop: Only parse NHA_OP_FLAGS for get messages that require it
  bpf: move sleepable flag from bpf_prog_aux to bpf_prog
  bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
  selftests/bpf: Add kprobe multi triggering benchmarks
  ptp: Move from simple ida to xarray
  vxlan: Remove generic .ndo_get_stats64
  vxlan: Do not alloc tstats manually
  devlink: Add comments to use netlink gen tool
  nfp: flower: handle acti_netdevs allocation failure
  net/packet: Add getsockopt support for PACKET_COPY_THRESH
  net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
  selftests/bpf: Add bpf_arena_htab test.
  selftests/bpf: Add bpf_arena_list test.
  selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
  bpf: Add helper macro bpf_addr_space_cast()
  libbpf: Recognize __arena global variables.
  bpftool: Recognize arena map type
  ...

Pull documentation updates from Jonathan Corbet:
 "A moderatly busy cycle for development this time around.

   - Some cleanup of the main index page for easier navigation

   - Rework some of the other top-level pages for better readability
     and, with luck, fewer merge conflicts in the future.

   - Submit-checklist improvements, hopefully the first of many.

   - New Italian translations

   - A fair number of kernel-doc fixes and improvements. We have also
     dropped the recommendation to use an old version of Sphinx.

   - A new document from Thorsten on bisection

  ... and lots of fixes and updates"

* tag 'docs-6.9' of git://git.lwn.net/linux: (54 commits)
  docs: verify/bisect: fixes, finetuning, and support for Arch
  docs: Makefile: Add dependency to $(YNL_INDEX) for targets other than htmldocs
  docs: Move ja_JP/howto.rst to ja_JP/process/howto.rst
  docs: submit-checklist: use subheadings
  docs: submit-checklist: structure by category
  docs: new text on bisecting which also covers bug validation
  docs: drop the version constraints for sphinx and dependencies
  docs: kerneldoc-preamble.sty: Remove code for Sphinx <2.4
  docs: Restore "smart quotes" for quotes
  docs/zh_CN: accurate translation of "function"
  docs: Include simplified link titles in main index
  docs: Correct formatting of title in admin-guide/index.rst
  docs: kernel_feat.py: fix build error for missing files
  MAINTAINERS: Set the field name for subsystem profile section
  kasan: Add documentation for CONFIG_KASAN_EXTRA_INFO
  Fixed case issue with 'fault-injection' in documentation
  kernel-doc: handle #if in enums as well
  Documentation: update mailing list addresses
  doc: kerneldoc.py: fix indentation
  scripts/kernel-doc: simplify signature printing
  ...

Pull audit updates from Paul Moore:
 "Two small audit patches:

   - Use the KMEM_CACHE() macro instead of kmem_cache_create()

     The guidance appears to be to use the KMEM_CACHE() macro when
     possible and there is no reason why we can't use the macro, so
     let's use it.

   - Remove an unnecessary assignment in audit_dupe_lsm_field()

     A return value variable was assigned a value in its declaration,
     but the declaration value is overwritten before the return value
     variable is ever referenced; drop the assignment at declaration
     time"

* tag 'audit-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: use KMEM_CACHE() instead of kmem_cache_create()
  audit: remove unnecessary assignment in audit_dupe_lsm_field()

Pull smack updates from Casey Schaufler:

 - Improvements to the initialization of in-memory inodes

 - A fix in ramfs to propery ensure the initialization of in-memory
   inodes

 - Removal of duplicated code in smack_cred_transfer()

* tag 'Smack-for-6.9' of https://github.com/cschaufler/smack-next:
  Smack: use init_task_smack() in smack_cred_transfer()
  ramfs: Initialize security of in-memory inodes
  smack: Initialize the in-memory inode in smack_inode_init_security()
  smack: Always determine inode labels in smack_inode_init_security()
  smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity()
  smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr()

Pull seccomp updates from Kees Cook:
 "There are no core kernel changes here; it's entirely selftests and
  samples:

   - Improve reliability of selftests (Terry Tritton, Kees Cook)

   - Fix strict-aliasing warning in samples (Arnd Bergmann)"

* tag 'seccomp-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  samples: user-trap: fix strict-aliasing warning
  selftests/seccomp: Pin benchmark to single CPU
  selftests/seccomp: user_notification_addfd check nextfd is available
  selftests/seccomp: Change the syscall used in KILL_THREAD test
  selftests/seccomp: Handle EINVAL on unshare(CLONE_NEWPID)

Pull hardening updates from Kees Cook:
 "As is pretty normal for this tree, there are changes all over the
  place, especially for small fixes, selftest improvements, and improved
  macro usability.

  Some header changes ended up landing via this tree as they depended on
  the string header cleanups. Also, a notable set of changes is the work
  for the reintroduction of the UBSAN signed integer overflow sanitizer
  so that we can continue to make improvements on the compiler side to
  make this sanitizer a more viable future security hardening option.

  Summary:

   - string.h and related header cleanups (Tanzir Hasan, Andy
     Shevchenko)

   - VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev,
     Harshit Mogalapalli)

   - selftests/powerpc: Fix load_unaligned_zeropad build failure
     (Michael Ellerman)

   - hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn)

   - Handle tail call optimization better in LKDTM (Douglas Anderson)

   - Use long form types in overflow.h (Andy Shevchenko)

   - Add flags param to string_get_size() (Andy Shevchenko)

   - Add Coccinelle script for potential struct_size() use (Jacob
     Keller)

   - Fix objtool corner case under KCFI (Josh Poimboeuf)

   - Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng)

   - Add str_plural() helper (Michal Wajdeczko, Kees Cook)

   - Ignore relocations in .notes section

   - Add comments to explain how __is_constexpr() works

   - Fix m68k stack alignment expectations in stackinit Kunit test

   - Convert string selftests to KUnit

   - Add KUnit tests for fortified string functions

   - Improve reporting during fortified string warnings

   - Allow non-type arg to type_max() and type_min()

   - Allow strscpy() to be called with only 2 arguments

   - Add binary mode to leaking_addresses scanner

   - Various small cleanups to leaking_addresses scanner

   - Adding wrapping_*() arithmetic helper

   - Annotate initial signed integer wrap-around in refcount_t

   - Add explicit UBSAN section to MAINTAINERS

   - Fix UBSAN self-test warnings

   - Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL

   - Reintroduce UBSAN's signed overflow sanitizer"

* tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits)
  selftests/powerpc: Fix load_unaligned_zeropad build failure
  string: Convert helpers selftest to KUnit
  string: Convert selftest to KUnit
  sh: Fix build with CONFIG_UBSAN=y
  compiler.h: Explain how __is_constexpr() works
  overflow: Allow non-type arg to type_max() and type_min()
  VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
  lib/string_helpers: Add flags param to string_get_size()
  x86, relocs: Ignore relocations in .notes section
  objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks
  overflow: Use POD in check_shl_overflow()
  lib: stackinit: Adjust target string to 8 bytes for m68k
  sparc: vdso: Disable UBSAN instrumentation
  kernel.h: Move lib/cmdline.c prototypes to string.h
  leaking_addresses: Provide mechanism to scan binary files
  leaking_addresses: Ignore input device status lines
  leaking_addresses: Use File::Temp for /tmp files
  MAINTAINERS: Update LEAKING_ADDRESSES details
  fortify: Improve buffer overflow reporting
  fortify: Add KUnit tests for runtime overflows
  ...

Pull execve updates from Kees Cook:

 - Drop needless error path code in remove_arg_zero() (Li kunyu, Kees
   Cook)

 - binfmt_elf_efpic: Don't use missing interpreter's properties (Max
   Filippov)

 - Use /bin/bash for execveat selftests

* tag 'execve-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Simplify remove_arg_zero() error path
  selftests/exec: Perform script checks with /bin/bash
  exec: Delete unnecessary statements in remove_arg_zero()
  fs: binfmt_elf_efpic: don't use missing interpreter's properties

Pull pstore updates from Kees Cook:

 - Make PSTORE_RAM available by default on arm64 (Nícolas F R A Prado)

 - Allow for dynamic initialization in modular build (Guilherme G
   Piccoli)

 - Add missing allocation failure check (Kunwu Chan)

 - Avoid duplicate memory zeroing (Christophe JAILLET)

 - Avoid potential double-free during pstorefs umount

* tag 'pstore-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/zone: Don't clear memory twice
  pstore/zone: Add a null pointer check to the psz_kmsg_read
  efi: pstore: Allow dynamic initialization based on module parameter
  arm64: defconfig: Enable PSTORE_RAM
  pstore/ram: Register to module device table
  pstore: inode: Only d_invalidate() is needed

Pull nfsd updates from Chuck Lever:
 "The bulk of the patches for this release are optimizations, code
  clean-ups, and minor bug fixes.

  One new feature to mention is that NFSD administrators now have the
  ability to revoke NFSv4 open and lock state. NFSD's NFSv3 support has
  had this capability for some time.

  As always I am grateful to NFSD contributors, reviewers, and testers"

* tag 'nfsd-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (75 commits)
  NFSD: Clean up nfsd4_encode_replay()
  NFSD: send OP_CB_RECALL_ANY to clients when number of delegations reaches its limit
  NFSD: Document nfsd_setattr() fill-attributes behavior
  nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr()
  nfsd: Fix a regression in nfsd_setattr()
  NFSD: OP_CB_RECALL_ANY should recall both read and write delegations
  NFSD: handle GETATTR conflict with write delegation
  NFSD: add support for CB_GETATTR callback
  NFSD: Document the phases of CREATE_SESSION
  NFSD: Fix the NFSv4.1 CREATE_SESSION operation
  nfsd: clean up comments over nfs4_client definition
  svcrdma: Add Write chunk WRs to the RPC's Send WR chain
  svcrdma: Post WRs for Write chunks in svc_rdma_sendto()
  svcrdma: Post the Reply chunk and Send WR together
  svcrdma: Move write_info for Reply chunks into struct svc_rdma_send_ctxt
  svcrdma: Post Send WR chain
  svcrdma: Fix retry loop in svc_rdma_send()
  svcrdma: Prevent a UAF in svc_rdma_send()
  svcrdma: Fix SQ wake-ups
  svcrdma: Increase the per-transport rw_ctx count
  ...

Pull erofs updates from Gao Xiang:
 "In this cycle, we introduce compressed inode support over fscache
  since a lot of native EROFS images are explicitly compressed so that
  EROFS over fscache can be more widely used even without Dragonfly
  Nydus [1].

  Apart from that, there are some folio conversions for compressed
  inodes available as well as a lockdep false positive fix.

  Summary:

   - Some folio conversions for compressed inodes;

   - Add compressed inode support over fscache;

   - Fix lockdep false positives of erofs_pseudo_mnt"

Link: https://nydus.dev [1]

* tag 'erofs-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: support compressed inodes over fscache
  erofs: make iov_iter describe target buffers over fscache
  erofs: fix lockdep false positives on initializing erofs_pseudo_mnt
  erofs: refine managed cache operations to folios
  erofs: convert z_erofs_submissionqueue_endio() to folios
  erofs: convert z_erofs_fill_bio_vec() to folios
  erofs: get rid of `justfound` debugging tag
  erofs: convert z_erofs_do_read_page() to folios
  erofs: convert z_erofs_onlinepage_.* to folios

Pull fsverity update from Eric Biggers:
 "Slightly improve data verification performance by eliminating an
  unnecessary lock"

* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
  fsverity: remove hash page spin lock

Pull fscrypt updates from Eric Biggers:
 "Fix flakiness in a test by releasing the quota synchronously when a
  key is removed, and other minor cleanups"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux:
  fscrypt: shrink the size of struct fscrypt_inode_info slightly
  fscrypt: write CBC-CTS instead of CTS-CBC
  fscrypt: clear keyring before calling key_put()
  fscrypt: explicitly require that inode->i_blkbits be set

Pull affs update from David Sterba:
 "One change to AFFS that removes use of SLAB_MEM_SPREAD, which is going
  to be removed from MM code"

* tag 'affs-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  affs: remove SLAB_MEM_SPREAD flag usage

Pull btrfs updates from David Sterba:
 "Mostly stabilization, refactoring and cleanup changes. There rest are
  minor performance optimizations due to caching or lock contention
  reduction and a few notable fixes.

  Performance improvements:

   - minor speedup in logging when repeatedly allocated structure is
     preallocated only once, improves latency and decreases lock
     contention

   - minor throughput increase (+6%), reduced lock contention after
     clearing delayed allocation bits, applies to several common
     workload types

   - skip full quota rescan if a new relation is added in the same
     transaction

  Fixes:

   - zstd fix for inline compressed file in subpage mode, updated
     version from the 6.8 time

   - proper qgroup inheritance ioctl parameter validation

   - more fiemap followup fixes after reduced locking done in 6.8:
      - fix race when detecting delalloc ranges

  Core changes:

   - more debugging code:
      - added assertions for a very rare crash in raid56 calculation
      - tree-checker dumps page state to give more insights into
        possible reference counting issues

   - add checksum calculation offloading sysfs knob, for now enabled
     under DEBUG only to determine a good heuristic for deciding the
     offload or synchronous, depends on various factors (block group
     profile, device speed) and is not as clear as initially thought
     (checksum type)

   - error handling improvements, added assertions

   - more page to folio conversion (defrag, truncate), cached size and
     shift

   - preparation for more fine grained locking of sectors in subpage
     mode

   - cleanups and refactoring:
      - include cleanups, forward declarations
      - pointer-to-structure helpers
      - redundant argument removals
      - removed unused code
      - slab cache updates, last use of SLAB_MEM_SPREAD removed"

* tag 'for-6.9-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
  btrfs: reuse cloned extent buffer during fiemap to avoid re-allocations
  btrfs: fix race when detecting delalloc ranges during fiemap
  btrfs: fix off-by-one chunk length calculation at contains_pending_extent()
  btrfs: qgroup: allow quick inherit if snapshot is created and added to the same parent
  btrfs: qgroup: validate btrfs_qgroup_inherit parameter
  btrfs: include device major and minor numbers in the device scan notice
  btrfs: mark btrfs_put_caching_control() static
  btrfs: remove SLAB_MEM_SPREAD flag use
  btrfs: qgroup: always free reserved space for extent records
  btrfs: tree-checker: dump the page status if hit something wrong
  btrfs: compression: remove dead comments in btrfs_compress_heuristic()
  btrfs: subpage: make writer lock utilize bitmap
  btrfs: subpage: make reader lock utilize bitmap
  btrfs: unexport btrfs_subpage_start_writer() and btrfs_subpage_end_and_test_writer()
  btrfs: pass a valid extent map cache pointer to __get_extent_map()
  btrfs: merge btrfs_del_delalloc_inode() helpers
  btrfs: pass btrfs_device to btrfs_scratch_superblocks()
  btrfs: handle transaction commit errors in flush_reservations()
  btrfs: use KMEM_CACHE() to create btrfs_free_space cache
  btrfs: use KMEM_CACHE() to create delayed ref caches
  ...

Pull zonefs update from Damien Le Moal:

 - A single change for this cycle to convert zonefs to use the new
   mount API

* tag 'zonefs-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: convert zonefs to use the new mount api

Pull asm-generic updates from Arnd Bergmann:
 "Just two small updates this time:

   - A series I did to unify the definition of PAGE_SIZE through
     Kconfig, intended to help with a vdso rework that needs the
     constant but cannot include the normal kernel headers when building
     the compat VDSO on arm64 and potentially others

   - a patch from Yan Zhao to remove the pfn_to_virt() definitions from
     a couple of architectures after finding they were both incorrect
     and entirely unused"

* tag 'asm-generic-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  arch: define CONFIG_PAGE_SIZE_*KB on all architectures
  arch: simplify architecture specific page size configuration
  arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitions
  mm: Remove broken pfn_to_virt() on arch csky/hexagon/openrisc

Pull ARM defconfig updates from Arnd Bergmann:
 "This has the usual updates to enable platform specific driver modules
  as new hardware gets supported, as well as an update to the
  virt.config fragment so we disable all newly added platforms again"

* tag 'soc-defconfig-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (24 commits)
  arm64: defconfig: Enable support for cbmem entries in the coreboot table
  ARM: defconfig: enable STMicroelectronics accelerometer and gyro for Exynos
  arm64: defconfig: drop ext2 filesystem and redundant ext3
  arm64: defconfig: Enable Rockchip HDMI/eDP Combo PHY
  arm64: defconfig: Enable Wave5 Video Encoder/Decoder
  arm64: config: disable new platforms in virt.config
  arm64: defconfig: Enable QCOM PBS
  arm64: deconfig: enable Goodix Berlin SPI touchscreen driver as module
  arm64: defconfig: Enable X1E80100 multimedia clock controllers configs
  arm64: defconfig: Enable GCC and interconnect for QDU1000/QRU1000
  arm64: defconfig: enable i.MX8MP ldb bridge
  arm64: defconfig: enable the vf610 gpio driver
  ARM: imx_v6_v7_defconfig: enable the vf610 gpio driver
  ARM: multi_v7_defconfig: Add more TI Keystone support
  arm64: defconfig: enable WCD939x USBSS driver as module
  arm64: defconfig: enable audio drivers for SM8650 QRD board
  arm64: defconfig: Enable Qualcomm interconnect providers
  ARM: multi_v7_defconfig: Enable BACKLIGHT_CLASS_DEVICE
  arm64: defconfig: Enable i.MX8QXP device drivers
  ARM: multi_v7_defconfig: Add more TI Keystone support
  ...

Pull ARM SoC code updates from Arnd Bergmann:
 "These are mostly minor updates, including a number of kerneldoc fixes
  from Randy Dunlap across multiple platforms. OMAP gets a few bugfixes,
  and the MAINTAINERS file gets updated for AMD Zynq and NXP S32G"

* tag 'soc-arm-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (23 commits)
  ARM: s32c: update MAINTAINERS entry
  ARM: AM33xx: PRM: Implement REBOOT_COLD
  ARM: AM33xx: PRM: Remove redundand defines
  ARM: omap1: remove duplicated 'select ARCH_OMAP'
  ARM: s3c64xx: make bus_type const
  ARM: imx: Remove usage of the deprecated ida_simple_xx() API
  ARM: OMAP2+: fix kernel-doc warnings
  ARM: OMAP2+: fix kernel-doc warnings
  ARM: OMAP2+: fix a kernel-doc warning
  ARM: OMAP2+: PRM: fix kernel-doc warnings
  ARM: OMAP2+: prm44xx: fix a kernel-doc warning
  ARM: OMAP2+: pmic-cpcap: fix kernel-doc warnings
  ARM: OMAP2+: hwmod: fix kernel-doc warnings
  ARM: OMAP2+: hwmod: remove misuse of kernel-doc
  ARM: OMAP2+: CMINST: use matching function name in kernel-doc
  ARM: OMAP2+: cm33xx: use matching function name in kernel-doc
  ARM: OMAP2+: clock: fix a function name in kernel-doc
  ARM: OMAP2+: clockdomain: fix kernel-doc warnings
  ARM: OMAP2+: am33xx-restart: fix function name in kernel-doc
  soc: xilinx: update maintainer of event manager driver
  ...

Pull ARM SoC driver updates from Arnd Bergmann:
 "This is the usual mix of updates for drivers that are used on (mostly
  ARM) SoCs with no other top-level subsystem tree, including:

   - The SCMI firmware subsystem gains support for version 3.2 of the
     specification and updates to the notification code

   - Feature updates for Tegra and Qualcomm platforms for added hardware
     support

   - A number of platforms get soc_device additions for identifying
     newly added chips from Renesas, Qualcomm, Mediatek and Google

   - Trivial improvements for firmware and memory drivers amongst
     others, in particular 'const' annotations throughout multiple
     subsystems"

* tag 'soc-drivers-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (96 commits)
  tee: make tee_bus_type const
  soc: qcom: aoss: add missing kerneldoc for qmp members
  soc: qcom: geni-se: drop unused kerneldoc struct geni_wrapper param
  soc: qcom: spm: fix building with CONFIG_REGULATOR=n
  bus: ti-sysc: constify the struct device_type usage
  memory: stm32-fmc2-ebi: keep power domain on
  memory: stm32-fmc2-ebi: add MP25 RIF support
  memory: stm32-fmc2-ebi: add MP25 support
  memory: stm32-fmc2-ebi: check regmap_read return value
  dt-bindings: memory-controller: st,stm32: add MP25 support
  dt-bindings: bus: imx-weim: convert to YAML
  watchdog: s3c2410_wdt: use exynos_get_pmu_regmap_by_phandle() for PMU regs
  soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs
  MAINTAINERS: Update SCMI entry with HWMON driver
  MAINTAINERS: samsung: gs101: match patches touching Google Tensor SoC
  memory: tegra: Fix indentation
  memory: tegra: Add BPMP and ICC info for DLA clients
  memory: tegra: Correct DLA client names
  dt-bindings: memory: renesas,rpc-if: Document R-Car V4M support
  firmware: arm_scmi: Update the supported clock protocol version
  ...

Pull SoC device tree updates from Arnd Bergmann:
 "There is very little going on with new SoC support this time, all the
  new chips are variations of others that we already support, and they
  are all based on ARMv8 cores:

   - Mediatek MT7981B (Filogic 820) and MT7988A (Filogic 880) are
     networking SoCs designed to be used in wireless routers, similar to
     the already supported MT7986A (Filogic 830).

   - NXP i.MX8DXP is a variant of i.MX8QXP, with two CPU cores less.
     These are used in many embedded and industrial applications.

   - Renesas R8A779G2 (R-Car V4H ES2.0) and R8A779H0 (R-Car V4M) are
     automotive SoCs.

   - TI J722S is another automotive variant of its K3 family, related to
     the AM62 series.

  There are a total of 7 new arm32 machines and 45 arm64 ones, including

   - Two Android phones based on the old Tegra30 chip

   - Two machines using Cortex-A53 SoCs from Allwinner, a mini PC and a
     SoM development board

   - A set-top box using Amlogic Meson G12A S905X2

   - Eight embedded board using NXP i.MX6/8/9

   - Three machines using Mediatek network router chips

   - Ten Chromebooks, all based on Mediatek MT8186

   - One development board based on Mediatek MT8395 (Genio 1200)

   - Seven tablets and phones based on Qualcomm SoCs, most of them from
     Samsung.

   - A third development board for Qualcomm SM8550 (Snapdragon 8 Gen 2)

   - Three variants of the "White Hawk" board for Renesas automotive
     SoCs

   - Ten Rockchips RK35xx based machines, including NAS, Tablet, Game
     console and industrial form factors.

   - Three evaluation boards for TI K3 based SoCs

  The other changes are mainly the usual feature additions for existing
  hardware, cleanups, and dtc compile time fixes. One notable change is
  the inclusion of PowerVR SGX GPU nodes on TI SoCs"

* tag 'soc-dt-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (824 commits)
  riscv: dts: Move BUILTIN_DTB_SOURCE to common Kconfig
  riscv: dts: starfive: jh7100: fix root clock names
  ARM: dts: samsung: exynos4412: decrease memory to account for unusable region
  arm64: dts: qcom: sm8250-xiaomi-elish: set rotation
  arm64: dts: qcom: sm8650: Fix SPMI channels size
  arm64: dts: qcom: sm8550: Fix SPMI channels size
  arm64: dts: rockchip: Fix name for UART pin header on qnap-ts433
  arm: dts: marvell: clearfog-gtr-l8: align port numbers with enclosure
  arm: dts: marvell: clearfog-gtr-l8: add support for second sfp connector
  dt-bindings: soc: renesas: renesas-soc: Add pattern for gray-hawk
  dtc: Enable dtc interrupt_provider check
  arm64: dts: st: add video encoder support to stm32mp255
  arm64: dts: st: add video decoder support to stm32mp255
  ARM: dts: stm32: enable crypto accelerator on stm32mp135f-dk
  ARM: dts: stm32: enable CRC on stm32mp135f-dk
  ARM: dts: stm32: add CRC on stm32mp131
  ARM: dts: add stm32f769-disco-mb1166-reva09
  ARM: dts: stm32: add display support on stm32f769-disco
  ARM: dts: stm32: rename mmc_vcard to vcc-3v3 on stm32f769-disco
  ARM: dts: stm32: add DSI support on stm32f769
  ...

Pull m68k updates from Geert Uytterhoeven:

 - Make the Zorro bus type constant

 - defconfig updates

* tag 'm68k-for-v6.9-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: defconfig: Update defconfigs for v6.8-rc1
  zorro: Make zorro_bus_type const

Pull s390 updates from Heiko Carstens:

 - Various virtual vs physical address usage fixes

 - Fix error handling in Processor Activity Instrumentation device
   driver, and export number of counters with a sysfs file

 - Allow for multiple events when Processor Activity Instrumentation
   counters are monitored in system wide sampling

 - Change multiplier and shift values of the Time-of-Day clock source to
   improve steering precision

 - Remove a couple of unneeded GFP_DMA flags from allocations

 - Disable mmap alignment if randomize_va_space is also disabled, to
   avoid a too small heap

 - Various changes to allow s390 to be compiled with LLVM=1, since
   ld.lld and llvm-objcopy will have proper s390 support witch clang 19

 - Add __uninitialized macro to Compiler Attributes. This is helpful
   with s390's FPU code where some users have up to 520 byte stack
   frames. Clearing such stack frames (if INIT_STACK_ALL_PATTERN or
   INIT_STACK_ALL_ZERO is enabled) before they are used contradicts the
   intention (performance improvement) of such code sections.

 - Convert switch_to() to an out-of-line function, and use the generic
   switch_to header file

 - Replace the usage of s390's debug feature with pr_debug() calls
   within the zcrypt device driver

 - Improve hotplug support of the Adjunct Processor device driver

 - Improve retry handling in the zcrypt device driver

 - Various changes to the in-kernel FPU code:

     - Make in-kernel FPU sections preemptible

     - Convert various larger inline assemblies and assembler files to
       C, mainly by using singe instruction inline assemblies. This
       increases readability, but also allows makes it easier to add
       proper instrumentation hooks

     - Cleanup of the header files

 - Provide fast variants of csum_partial() and
   csum_partial_copy_nocheck() based on vector instructions

 - Introduce and use a lock to synchronize accesses to zpci device data
   structures to avoid inconsistent states caused by concurrent accesses

 - Compile the kernel without -fPIE. This addresses the following
   problems if the kernel is compiled with -fPIE:

     - It uses dynamic symbols (.dynsym), for which the linker refuses
       to allow more than 64k sections. This can break features which
       use '-ffunction-sections' and '-fdata-sections', including
       kpatch-build and function granular KASLR

     - It unnecessarily uses GOT relocations, adding an extra layer of
       indirection for many memory accesses

 - Fix shared_cpu_list for CPU private L2 caches, which incorrectly were
   reported as globally shared

* tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (117 commits)
  s390/tools: handle rela R_390_GOTPCDBL/R_390_GOTOFF64
  s390/cache: prevent rebuild of shared_cpu_list
  s390/crypto: remove retry loop with sleep from PAES pkey invocation
  s390/pkey: improve pkey retry behavior
  s390/zcrypt: improve zcrypt retry behavior
  s390/zcrypt: introduce retries on in-kernel send CPRB functions
  s390/ap: introduce mutex to lock the AP bus scan
  s390/ap: rework ap_scan_bus() to return true on config change
  s390/ap: clarify AP scan bus related functions and variables
  s390/ap: rearm APQNs bindings complete completion
  s390/configs: increase number of LOCKDEP_BITS
  s390/vfio-ap: handle hardware checkstop state on queue reset operation
  s390/pai: change sampling event assignment for PMU device driver
  s390/boot: fix minor comment style damages
  s390/boot: do not check for zero-termination relocation entry
  s390/boot: make type of __vmlinux_relocs_64_start|end consistent
  s390/boot: sanitize kaslr_adjust_relocs() function prototype
  s390/boot: simplify GOT handling
  s390: vmlinux.lds.S: fix .got.plt assertion
  s390/boot: workaround current 'llvm-objdump -t -j ...' behavior
  ...

Pull x86 boot updates from Ingo Molnar:

 - Continuing work by Ard Biesheuvel to improve the x86 early startup
   code, with the long-term goal to make it position independent:

      - Get rid of early accesses to global objects, either by moving
        them to the stack, deferring the access until later, or dropping
        the globals entirely

      - Move all code that runs early via the 1:1 mapping into
        .head.text, and move code that does not out of it, so that build
        time checks can be added later to ensure that no inadvertent
        absolute references were emitted into code that does not
        tolerate them

      - Remove fixup_pointer() and occurrences of __pa_symbol(), which
        rely on the compiler emitting absolute references, which is not
        guaranteed

 - Improve the early console code

 - Add early console message about ignored NMIs, so that users are at
   least warned about their existence - even if we cannot do anything
   about them

 - Improve the kexec code's kernel load address handling

 - Enable more X86S (simplified x86) bits

 - Simplify early boot GDT handling

 - Micro-optimize the boot code a bit

 - Misc cleanups

* tag 'x86-boot-2024-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86/sev: Move early startup code into .head.text section
  x86/sme: Move early SME kernel encryption handling into .head.text
  x86/boot: Move mem_encrypt= parsing to the decompressor
  efi/libstub: Add generic support for parsing mem_encrypt=
  x86/startup_64: Simplify virtual switch on primary boot
  x86/startup_64: Simplify calculation of initial page table address
  x86/startup_64: Defer assignment of 5-level paging global variables
  x86/startup_64: Simplify CR4 handling in startup code
  x86/boot: Use 32-bit XOR to clear registers
  efi/x86: Set the PE/COFF header's NX compat flag unconditionally
  x86/boot/64: Load the final kernel GDT during early boot directly, remove startup_gdt[]
  x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]
  x86/boot/64: Use RIP_REL_REF() to access early page tables
  x86/boot/64: Use RIP_REL_REF() to access '__supported_pte_mask'
  x86/boot/64: Use RIP_REL_REF() to access early_dynamic_pgts[]
  x86/boot/64: Use RIP_REL_REF() to assign 'phys_base'
  x86/boot/64: Simplify global variable accesses in GDT/IDT programming
  x86/trampoline: Bypass compat mode in trampoline_start64() if not needed
  kexec: Allocate kernel above bzImage's pref_address
  x86/boot: Add a message about ignored early NMIs
  ...

Pull x86 APIC fixup from Dave Hansen:
 "Revert VERW fixed addressing patch.

  The reverted commit is not x86/apic material and was cruft left over
  from a merge.

  I believe the sequence of events went something like this:

   - The commit in question was added to x86/urgent

   - x86/urgent was merged into x86/apic to resolve a conflict

   - The commit was zapped from x86/urgent, but *not* from x86/apic

   - x86/apic got pullled (yesterday)

  I think we need to be a bit more vigilant when zapping things to make
  sure none of the other branches are depending on the zapped material"

* tag 'x86-apic-2024-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86/bugs: Use fixed addressing for VERW operand"

Pull x86 RFDS mitigation from Dave Hansen:
 "RFDS is a CPU vulnerability that may allow a malicious userspace to
  infer stale register values from kernel space. Kernel registers can
  have all kinds of secrets in them so the mitigation is basically to
  wait until the kernel is about to return to userspace and has user
  values in the registers. At that point there is little chance of
  kernel secrets ending up in the registers and the microarchitectural
  state can be cleared.

  This leverages some recent robustness fixes for the existing MDS
  vulnerability. Both MDS and RFDS use the VERW instruction for
  mitigation"

* tag 'rfds-for-linus-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM/x86: Export RFDS_NO and RFDS_CLEAR to guests
  x86/rfds: Mitigate Register File Data Sampling (RFDS)
  Documentation/hw-vuln: Add documentation for RFDS
  x86/mmio: Disable KVM mitigation when X86_FEATURE_CLEAR_CPU_BUF is set

This was reverts commit 8009479e.

It was originally in x86/urgent, but was deemed wrong so got zapped.
But in the meantime, x86/urgent had been merged into x86/apic to
resolve a conflict.  I didn't notice the merge so didn't zap it
from x86/apic and it managed to make it up with the x86/apic
material.

The reverted commit is known to cause some KASAN problems.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>