commit 76a6d5cd upstream.

There are a few cases where cloning an inline extent requires copying data
into a page of the destination inode. For these cases we are allocating
the required data and metadata space while holding a leaf locked. This can
result in a deadlock when we are low on available space because allocating
the space may flush delalloc and two deadlock scenarios can happen:

1) When starting writeback for an inode with a very small dirty range that
   fits in an inline extent, we deadlock during the writeback when trying
   to insert the inline extent, at cow_file_range_inline(), if the extent
   is going to be located in the leaf for which we are already holding a
   read lock;

2) After successfully starting writeback, for non-inline extent cases,
   the async reclaim thread will hang waiting for an ordered extent to
   complete if the ordered extent completion needs to modify the leaf
   for which the clone task is holding a read lock (for adding or
   replacing file extent items). So the cloning task will wait forever
   on the async reclaim thread to make progress, which in turn is
   waiting for the ordered extent completion which in turn is waiting
   to acquire a write lock on the same leaf.

So fix this by making sure we release the path (and therefore the leaf)
every time we need to copy the inline extent's data into a page of the
destination inode, as by that time we do not need to have the leaf locked.

Fixes: 05a5a762

 ("Btrfs: implement full reflink support for inline extents")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dc09ef35

 upstream.

Error injection stress uncovered a problem where we'd leave a dangling
inode ref if we failed during a rename_exchange.  This happens because
we insert the inode ref for one side of the rename, and then for the
other side.  If this second inode ref insert fails we'll leave the first
one dangling and leave a corrupt file system behind.  Fix this by
aborting if we did the insert for the first inode ref.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 011b28ac

 upstream.

This function has the following pattern

	while (1) {
		ret = whatever();
		if (ret)
			goto out;
	}
	ret = 0
out:
	return ret;

However several places in this while loop we simply break; when there's
a problem, thus clearing the return value, and in one case we do a
return -EIO, and leak the memory for the path.

Fix this by re-arranging the loop to deal with ret == 1 coming from
btrfs_search_slot, and then simply delete the

	ret = 0;
out:

bit so everybody can break if there is an error, which will allow for
proper error handling to occur.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 856bd270

 upstream.

We are unconditionally returning 0 in cleanup_ref_head, despite the fact
that btrfs_del_csums could fail.  We need to return the error so the
transaction gets aborted properly, fix this by returning ret from
btrfs_del_csums in cleanup_ref_head.

Reviewed-by: Qu Wenruo <wqu@suse.com>
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b86652be

 upstream.

Error injection stress would sometimes fail with checksums on disk that
did not have a corresponding extent.  This occurred because the pattern
in btrfs_del_csums was

	while (1) {
		ret = btrfs_search_slot();
		if (ret < 0)
			break;
	}
	ret = 0;
out:
	btrfs_free_path(path);
	return ret;

If we got an error from btrfs_search_slot we'd clear the error because
we were breaking instead of goto out.  Instead of using goto out, simply
handle the cases where we may leave a random value in ret, and get rid
of the

	ret = 0;
out:

pattern and simply allow break to have the proper error reporting.  With
this fix we properly abort the transaction and do not commit thinking we
successfully deleted the csum.

Reviewed-by: Qu Wenruo <wqu@suse.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d61bec08

 upstream.

While doing error injection testing I saw that sometimes we'd get an
abort that wouldn't stop the current transaction commit from completing.
This abort was coming from finish ordered IO, but at this point in the
transaction commit we should have gotten an error and stopped.

It turns out the abort came from finish ordered io while trying to write
out the free space cache.  It occurred to me that any failure inside of
finish_ordered_io isn't actually raised to the person doing the writing,
so we could have any number of failures in this path and think the
ordered extent completed successfully and the inode was fine.

Fix this by marking the ordered extent with BTRFS_ORDERED_IOERR, and
marking the mapping of the inode with mapping_set_error, so any callers
that simply call fdatawait will also get the error.

With this we're seeing the IO error on the free space inode when we fail
to do the finish_ordered_io.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 82123a3d upstream.

When checking if the probed instruction is the suffix of a prefixed
instruction, we access the instruction at the previous word. If the
probed instruction is the very first word of a module, we can end up
trying to access an invalid page.

Fix this by skipping the check for all instructions at the beginning of
a page. Prefixed instructions cannot cross a 64-byte boundary and as
such, we don't expect to encounter a suffix as the very first word in a
page for kernel text. Even if there are prefixed instructions crossing
a page boundary (from a module, for instance), the instruction will be
illegal, so preventing probing on the suffix of such prefix instructions
isn't worthwhile.

Fixes: b4657f76

 ("powerpc/kprobes: Don't allow breakpoints on suffixes")
Cc: stable@vger.kernel.org # v5.8+
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0df9a032a05576a2fa8e97d1b769af2ff0eafbd6.1621416666.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7d65f9e8 upstream.

PIC interrupts do not support affinity setting and they can end up on
any online CPU. Therefore, it's required to mark the associated vectors
as system-wide reserved. Otherwise, the corresponding irq descriptors
are copied to the secondary CPUs but the vectors are not marked as
assigned or reserved. This works correctly for the IO/APIC case.

When the IO/APIC is disabled via config, kernel command line or lack of
enumeration then all legacy interrupts are routed through the PIC, but
nothing marks them as system-wide reserved vectors.

As a consequence, a subsequent allocation on a secondary CPU can result in
allocating one of these vectors, which triggers the BUG() in
apic_update_vector() because the interrupt descriptor slot is not empty.

Imran tried to work around that by marking those interrupts as allocated
when a CPU comes online. But that's wrong in case that the IO/APIC is
available and one of the legacy interrupts, e.g. IRQ0, has been switched to
PIC mode because then marking them as allocated will fail as they are
already marked as system vectors.

Stay consistent and update the legacy vectors after attempting IO/APIC
initialization and mark them as system vectors in case that no IO/APIC is
available.

Fixes: 69cde000

 ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Imran Khan <imran.f.khan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210519233928.2157496-1-imran.f.khan@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 07438603 upstream.

Releasing pinned BOs is illegal now. UVD 6 was missing from:
commit 2f40801d ("drm/amdgpu: make sure we unpin the UVD BO")

Fixes: 2f40801d

 ("drm/amdgpu: make sure we unpin the UVD BO")
Cc: stable@vger.kernel.org
Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dce3d8e1 upstream.

On QUERY2 IOCTL don't query counts of correctable
and uncorrectable errors, since when RAS is
enabled and supported on Vega20 server boards,
this takes insurmountably long time, in O(n^3),
which slows the system down to the point of it
being unusable when we have GUI up.

Fixes: ae363a21

 ("drm/amdgpu: Add a new flag to AMDGPU_CTX_OP_QUERY_STATE2")
Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alexander Deucher <Alexander.Deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4ac06a1e upstream.

It's possible to trigger NULL pointer dereference by local unprivileged
user, when calling getsockname() after failed bind() (e.g. the bind
fails because LLCP_SAP_MAX used as SAP):

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  CPU: 1 PID: 426 Comm: llcp_sock_getna Not tainted 5.13.0-rc2-next-20210521+ #9
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1 04/01/2014
  Call Trace:
   llcp_sock_getname+0xb1/0xe0
   __sys_getpeername+0x95/0xc0
   ? lockdep_hardirqs_on_prepare+0xd5/0x180
   ? syscall_enter_from_user_mode+0x1c/0x40
   __x64_sys_getpeername+0x11/0x20
   do_syscall_64+0x36/0x70
   entry_SYSCALL_64_after_hwframe+0x44/0xae

This can be reproduced with Syzkaller C repro (bind followed by
getpeername):
https://syzkaller.appspot.com/x/repro.c?x=14def446e00000

Cc: <stable@vger.kernel.org>
Fixes: d646960f

 ("NFC: Initial LLCP support")
Reported-by:  <syzbot+80fb126e7f7d8b1a5914@syzkaller.appspotmail.com>
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210531072138.5219-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 009767db upstream.

The first two bits of the CPUID leaf 0x8000001F EAX indicate whether SEV
or SME is supported, respectively. It's better to check whether SEV or
SME is actually supported before accessing the MSR_AMD64_SEV to check
whether SEV or SME is enabled.

This is both a bare-metal issue and a guest/VM issue. Since the first
generation Hygon Dhyana CPU doesn't support the MSR_AMD64_SEV, reading that
MSR results in a #GP - either directly from hardware in the bare-metal
case or via the hypervisor (because the RDMSR is actually intercepted)
in the guest/VM case, resulting in a failed boot. And since this is very
early in the boot phase, rdmsrl_safe()/native_read_msr_safe() can't be
used.

So check the CPUID bits first, before accessing the MSR.

 [ tlendacky: Expand and improve commit message. ]
 [ bp: Massage commit message. ]

Fixes: eab696d8

 ("x86/sev: Do not require Hypervisor CPUID bit for SEV guests")
Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org> # v5.10+
Link: https://lkml.kernel.org/r/20210602070207.2480-1-puwen@hygon.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9bfecd05 upstream.

While digesting the XSAVE-related horrors which got introduced with
the supervisor/user split, the recent addition of ENQCMD-related
functionality got on the radar and turned out to be similarly broken.

update_pasid(), which is only required when X86_FEATURE_ENQCMD is
available, is invoked from two places:

 1) From switch_to() for the incoming task

 2) Via a SMP function call from the IOMMU/SMV code

#1 is half-ways correct as it hacks around the brokenness of get_xsave_addr()
   by enforcing the state to be 'present', but all the conditionals in that
   code are completely pointless for that.

   Also the invocation is just useless overhead because at that point
   it's guaranteed that TIF_NEED_FPU_LOAD is set on the incoming task
   and all of this can be handled at return to user space.

#2 is broken beyond repair. The comment in the code claims that it is safe
   to invoke this in an IPI, but that's just wishful thinking.

   FPU state of a running task is protected by fregs_lock() which is
   nothing else than a local_bh_disable(). As BH-disabled regions run
   usually with interrupts enabled the IPI can hit a code section which
   modifies FPU state and there is absolutely no guarantee that any of the
   assumptions which are made for the IPI case is true.

   Also the IPI is sent to all CPUs in mm_cpumask(mm), but the IPI is
   invoked with a NULL pointer argument, so it can hit a completely
   unrelated task and unconditionally force an update for nothing.
   Worse, it can hit a kernel thread which operates on a user space
   address space and set a random PASID for it.

The offending commit does not cleanly revert, but it's sufficient to
force disable X86_FEATURE_ENQCMD and to remove the broken update_pasid()
code to make this dysfunctional all over the place. Anything more
complex would require more surgery and none of the related functions
outside of the x86 core code are blatantly wrong, so removing those
would be overkill.

As nothing enables the PASID bit in the IA32_XSS MSR yet, which is
required to make this actually work, this cannot result in a regression
except for related out of tree train-wrecks, but they are broken already
today.

Fixes: 20f0afd1

 ("x86/mmu: Allocate/free a PASID")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/87mtsd6gr9.ffs@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bac9c6fa upstream.

Recently we found that there is a lot MemFree left in /proc/meminfo
after do a lot of pages soft offline, it's not quite correct.

Before Oscar's rework of soft offline for free pages [1], if we soft
offline free pages, these pages are left in buddy with HWPoison flag,
and NR_FREE_PAGES is not updated immediately.  So the difference between
NR_FREE_PAGES and real number of available free pages is also even big
at the beginning.

However, with the workload running, when we catch HWPoison page in any
alloc functions subsequently, we will remove it from buddy, meanwhile
update the NR_FREE_PAGES and try again, so the NR_FREE_PAGES will get
more and more closer to the real number of available free pages.
(regardless of unpoison_memory())

Now, for offline free pages, after a successful call
take_page_off_buddy(), the page is no longer belong to buddy allocator,
and will not be used any more, but we missed accounting NR_FREE_PAGES in
this situation, and there is no chance to be updated later.

Do update in take_page_off_buddy() like rmqueue() does, but avoid double
counting if some one already set_migratetype_isolate() on the page.

[1]: commit 06be6ff3 ("mm,hwpoison: rework soft offline for free pages")

Link: https://lkml.kernel.org/r/20210526075247.11130-1-dinghui@sangfor.com.cn
Fixes: 06be6ff3

 ("mm,hwpoison: rework soft offline for free pages")
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 04f7ce3f upstream.

In pmd/pud_advanced_tests(), the vaddr is aligned up to the next pmd/pud
entry, and so it does not match the given pmdp/pudp and (aligned down)
pfn any more.

For s390, this results in memory corruption, because the IDTE
instruction used e.g.  in xxx_get_and_clear() will take the vaddr for
some calculations, in combination with the given pmdp.  It will then end
up with a wrong table origin, ending on ...ff8, and some of those
wrongly set low-order bits will also select a wrong pagetable level for
the index addition.  IDTE could therefore invalidate (or 0x20) something
outside of the page tables, depending on the wrongly picked index, which
in turn depends on the random vaddr.

As result, we sometimes see "BUG task_struct (Not tainted): Padding
overwritten" on s390, where one 0x5a padding value got overwritten with
0x7a.

Fix this by aligning down, similar to how the pmd/pud_aligned pfns are
calculated.

Link: https://lkml.kernel.org/r/20210525130043.186290-2-gerald.schaefer@linux.ibm.com
Fixes: a5c3b9ff

 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: <stable@vger.kernel.org>	[5.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6bba4471

 upstream.

When fallocate punches holes out of inode size, if original isize is in
the middle of last cluster, then the part from isize to the end of the
cluster will be zeroed with buffer write, at that time isize is not yet
updated to match the new size, if writeback is kicked in, it will invoke
ocfs2_writepage()->block_write_full_page() where the pages out of inode
size will be dropped.  That will cause file corruption.  Fix this by
zero out eof blocks when extending the inode size.

Running the following command with qemu-image 4.2.1 can get a corrupted
coverted image file easily.

    qemu-img convert -p -t none -T none -f qcow2 $qcow_image \
             -O qcow2 -o compat=1.1 $qcow_image.conv

The usage of fallocate in qemu is like this, it first punches holes out
of inode size, then extend the inode size.

    fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0
    fallocate(11, 0, 2276196352, 65536) = 0

v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html
v2: https://lore.kernel.org/linux-fsdevel/20210525093034.GB4112@quack2.suse.cz/T/

Link: https://lkml.kernel.org/r/20210528210648.9124-1-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0711f0d7 upstream.

During boot, kernel_init_freeable() initializes `cad_pid` to the init
task's struct pid.  Later on, we may change `cad_pid` via a sysctl, and
when this happens proc_do_cad_pid() will increment the refcount on the
new pid via get_pid(), and will decrement the refcount on the old pid
via put_pid().  As we never called get_pid() when we initialized
`cad_pid`, we decrement a reference we never incremented, can therefore
free the init task's struct pid early.  As there can be dangling
references to the struct pid, we can later encounter a use-after-free
(e.g.  when delivering signals).

This was spotted when fuzzing v5.13-rc3 with Syzkaller, but seems to
have been around since the conversion of `cad_pid` to struct pid in
commit 9ec52099 ("[PATCH] replace cad_pid by a struct pid") from the
pre-KASAN stone age of v2.6.19.

Fix this by getting a reference to the init task's struct pid when we
assign it to `cad_pid`.

Full KASAN splat below.

   ==================================================================
   BUG: KASAN: use-after-free in ns_of_pid include/linux/pid.h:153 [inline]
   BUG: KASAN: use-after-free in task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
   Read of size 4 at addr ffff23794dda0004 by task syz-executor.0/273

   CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1
   Hardware name: linux,dummy-virt (DT)
   Call trace:
    ns_of_pid include/linux/pid.h:153 [inline]
    task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509
    do_notify_parent+0x308/0xe60 kernel/signal.c:1950
    exit_notify kernel/exit.c:682 [inline]
    do_exit+0x2334/0x2bd0 kernel/exit.c:845
    do_group_exit+0x108/0x2c8 kernel/exit.c:922
    get_signal+0x4e4/0x2a88 kernel/signal.c:2781
    do_signal arch/arm64/kernel/signal.c:882 [inline]
    do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936
    work_pending+0xc/0x2dc

   Allocated by task 0:
    slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516
    slab_alloc_node mm/slub.c:2907 [inline]
    slab_alloc mm/slub.c:2915 [inline]
    kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920
    alloc_pid+0xdc/0xc00 kernel/pid.c:180
    copy_process+0x2794/0x5e18 kernel/fork.c:2129
    kernel_clone+0x194/0x13c8 kernel/fork.c:2500
    kernel_thread+0xd4/0x110 kernel/fork.c:2552
    rest_init+0x44/0x4a0 init/main.c:687
    arch_call_rest_init+0x1c/0x28
    start_kernel+0x520/0x554 init/main.c:1064
    0x0

   Freed by task 270:
    slab_free_hook mm/slub.c:1562 [inline]
    slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600
    slab_free mm/slub.c:3161 [inline]
    kmem_cache_free+0x224/0x8e0 mm/slub.c:3177
    put_pid.part.4+0xe0/0x1a8 kernel/pid.c:114
    put_pid+0x30/0x48 kernel/pid.c:109
    proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401
    proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591
    proc_sys_write+0x34/0x48 fs/proc/proc_sysctl.c:617
    call_write_iter include/linux/fs.h:1977 [inline]
    new_sync_write+0x3ac/0x510 fs/read_write.c:518
    vfs_write fs/read_write.c:605 [inline]
    vfs_write+0x9c4/0x1018 fs/read_write.c:585
    ksys_write+0x124/0x240 fs/read_write.c:658
    __do_sys_write fs/read_write.c:670 [inline]
    __se_sys_write fs/read_write.c:667 [inline]
    __arm64_sys_write+0x78/0xb0 fs/read_write.c:667
    __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
    invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]
    el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129
    do_el0_svc+0xf8/0x150 arch/arm64/kernel/syscall.c:168
    el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416
    el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432
    el0_sync+0x154/0x180 arch/arm64/kernel/entry.S:701

   The buggy address belongs to the object at ffff23794dda0000
    which belongs to the cache pid of size 224
   The buggy address is located 4 bytes inside of
    224-byte region [ffff23794dda0000, ffff23794dda00e0)
   The buggy address belongs to the page:
   page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4dda0
   head:(____ptrval____) order:1 compound_mapcount:0
   flags: 0x3fffc0000010200(slab|head)
   raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff23794d40d080
   raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
   page dumped because: kasan: bad access detected

   Memory state around the buggy address:
    ffff23794dd9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
    ffff23794dd9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
   >ffff23794dda0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
    ffff23794dda0080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
    ffff23794dda0100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
   ==================================================================

Link: https://lkml.kernel.org/r/20210524172230.38715-1-mark.rutland@arm.com
Fixes: 9ec52099

 ("[PATCH] replace cad_pid by a struct pid")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In branches to which 24d209db ("usb: dwc2: Fix hibernation between
host and device modes.") has been back-ported, the bus_suspended member
of struct dwc2_hsotg is only present in builds that support host-mode.
To avoid having to pull in several more non-Fix commits in order to
get it to compile, wrap the usage of the member in a macro conditional.

Fixes: 24d209db

 ("usb: dwc2: Fix hibernation between host and device modes.")
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b45f189a upstream.

When running generic/527 with fast_commit configuration, the following
issue is seen on Power.  With fast_commit, during ext4_fc_replay()
(which can be called from ext4_fill_super()), if inode eviction
happens then it can access an uninitialized percpu counter variable.

This patch adds the check before accessing the counters in
ext4_free_inode() path.

[  321.165371] run fstests generic/527 at 2021-04-29 08:38:43
[  323.027786] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: block_validity. Quota mode: none.
[  323.618772] BUG: Unable to handle kernel data access on read at 0x1fbd80000
[  323.619767] Faulting instruction address: 0xc000000000bae78c
cpu 0x1: Vector: 300 (Data Access) at [c000000010706ef0]
    pc: c000000000bae78c: percpu_counter_add_batch+0x3c/0x100
    lr: c0000000006d0bb0: ext4_free_inode+0x780/0xb90
    pid   = 5593, comm = mount
	ext4_free_inode+0x780/0xb90
	ext4_evict_inode+0xa8c/0xc60
	evict+0xfc/0x1e0
	ext4_fc_replay+0xc50/0x20f0
	do_one_pass+0xfe0/0x1350
	jbd2_journal_recover+0x184/0x2e0
	jbd2_journal_load+0x1c0/0x4a0
	ext4_fill_super+0x2458/0x4200
	mount_bdev+0x1dc/0x290
	ext4_mount+0x28/0x40
	legacy_get_tree+0x4c/0xa0
	vfs_get_tree+0x4c/0x120
	path_mount+0xcf8/0xd70
	do_mount+0x80/0xd0
	sys_mount+0x3fc/0x490
	system_call_exception+0x384/0x3d0
	system_call_common+0xec/0x278

Cc: stable@kernel.org
Fixes: 8016e29f

 ("ext4: fast commit recovery path")
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/6cceb9a75c54bef8fa9696c1b08c8df5ff6169e2.1619692410.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a8867f4e

 upstream.

Fix a memory leak discovered by syzbot when a file system is corrupted
with an illegally large s_log_groups_per_flex.

Reported-by:  <syzbot+aa12d6106ea4ca1b6aae@syzkaller.appspotmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20210412073837.1686-1-phil@philpotter.co.uk
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a7ba36bc upstream.

Fast commit recovery data on disk may not be aligned. So, when the
recovery code reads it, this patch makes sure that fast commit info
found on-disk is first memcpy-ed into an aligned variable before
accessing it. As a consequence of it, we also remove some macros that
could resulted in unaligned accesses.

Cc: stable@kernel.org
Fixes: 8016e29f

 ("ext4: fast commit recovery path")
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210519215920.2037527-1-harshads@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 082cd4ec

 upstream.

We got follow bug_on when run fsstress with injecting IO fault:
[130747.323114] kernel BUG at fs/ext4/extents_status.c:762!
[130747.323117] Internal error: Oops - BUG: 0 [#1] SMP
......
[130747.334329] Call trace:
[130747.334553]  ext4_es_cache_extent+0x150/0x168 [ext4]
[130747.334975]  ext4_cache_extents+0x64/0xe8 [ext4]
[130747.335368]  ext4_find_extent+0x300/0x330 [ext4]
[130747.335759]  ext4_ext_map_blocks+0x74/0x1178 [ext4]
[130747.336179]  ext4_map_blocks+0x2f4/0x5f0 [ext4]
[130747.336567]  ext4_mpage_readpages+0x4a8/0x7a8 [ext4]
[130747.336995]  ext4_readpage+0x54/0x100 [ext4]
[130747.337359]  generic_file_buffered_read+0x410/0xae8
[130747.337767]  generic_file_read_iter+0x114/0x190
[130747.338152]  ext4_file_read_iter+0x5c/0x140 [ext4]
[130747.338556]  __vfs_read+0x11c/0x188
[130747.338851]  vfs_read+0x94/0x150
[130747.339110]  ksys_read+0x74/0xf0

This patch's modification is according to Jan Kara's suggestion in:
https://patchwork.ozlabs.org/project/linux-ext4/patch/20210428085158.3728201-1-yebin10@huawei.com/
"I see. Now I understand your patch. Honestly, seeing how fragile is trying
to fix extent tree after split has failed in the middle, I would probably
go even further and make sure we fix the tree properly in case of ENOSPC
and EDQUOT (those are easily user triggerable).  Anything else indicates a
HW problem or fs corruption so I'd rather leave the extent tree as is and
don't try to fix it (which also means we will not create overlapping
extents)."

Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210506141042.3298679-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit afd09b61 upstream.

Buffer head references must be released before calling kill_bdev();
otherwise the buffer head (and its page referenced by b_data) will not
be freed by kill_bdev, and subsequently that bh will be leaked.

If blocksizes differ, sb_set_blocksize() will kill current buffers and
page cache by using kill_bdev(). And then super block will be reread
again but using correct blocksize this time. sb_set_blocksize() didn't
fully free superblock page and buffer head, and being busy, they were
not freed and instead leaked.

This can easily be reproduced by calling an infinite loop of:

  systemctl start <ext4_on_lvm>.mount, and
  systemctl stop <ext4_on_lvm>.mount

... since systemd creates a cgroup for each slice which it mounts, and
the bh leak get amplified by a dying memory cgroup that also never
gets freed, and memory consumption is much more easily noticed.

Fixes: ce40733c ("ext4: Check for return value from sb_set_blocksize")
Fixes: ac27a0ec

 ("ext4: initial copy of files from ext3")
Link: https://lore.kernel.org/r/20210521075533.95732-1-amakhalov@vmware.com
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8967b27a upstream.

Per schematic, both PU and SOC regulator are supplied from LTC3676 SW1
via VDDSOC_IN rail, add the PU input. Both VDD1P1, VDD2P5 are supplied
from LTC3676 SW2 via VDDHIGH_IN rail, add both inputs.

While no instability or problems are currently observed, the regulators
should be fully described in DT and that description should fully match
the hardware, else this might lead to unforseen issues later. Fix this.

Fixes: 52c7a088

 ("ARM: dts: imx6q: Add support for the DHCOM iMX6 SoM and PDK2")
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Ludwig Zenz <lzenz@dh-electronics.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0e4a4a08 upstream.

The FEC does not have a PHY so it should not have a phy-handle. It is
connected to the switch at RGMII level so we need a fixed-link sub-node
on both ends.

This was not a problem until the qca8k.c driver was converted to PHYLINK
by commit b3591c2a ("net: dsa: qca8k: Switch to PHYLINK instead of
PHYLIB"). That commit revealed the FEC configuration was not correct.

Fixes: 87489ec3

 ("ARM: dts: imx: Add Y Soft IOTA Draco, Hydra and Ursa boards")
Cc: stable@vger.kernel.org
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b8b90c17 upstream.

The patch_realtek.c needs to check if the power_state.event equals
PM_EVENT_SUSPEND, after using the direct-complete, the suspend() and
resume() will be skipped if the codec is already rt_suspended, in this
case, the patch_realtek.c will always get PM_EVENT_ON even the system
is really resumed from S3.

We could set power_state to PMSG_SUSPEND in the prepare(), if other
PM functions are called before complete(), those functions will
override power_state; if no other PM functions are called before
complete(), we could know the suspend() and resume() are skipped since
only S3 pm functions could be skipped by direct-complete, in this case
set power_state to PMSG_RESUME in the complete(). This could guarantee
the first time of calling hda_codec_runtime_resume() after complete()
has the correct power_state.

Fixes: 215a22ed

 ("ALSA: hda: Refactor codec PM to use direct-complete optimization")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20210602145424.3132-1-hui.wang@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 901be145

 upstream.

For the HP Pavilion 15-CK0xx, with audio subsystem ID 0x103c:0x841c,
adding a line in patch_realtek.c to apply the ALC269_FIXUP_HP_MUTE_LED_MIC3
fix activates the mute key LED.

Signed-off-by: Carlos M <carlos.marr.pz@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210531202026.35427-1-carlos.marr.pz@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9c1fe96b

 upstream.

snd_timer_notify1() calls the notification to each slave for a master
event, but it passes a wrong event number.  It should be +10 offset,
corresponding to SNDRV_TIMER_EVENT_MXXX, but it's incorrectly with
+100 offset.  Casually this was spotted by UBSAN check via syzkaller.

Reported-by:  <syzbot+d102fa5b35335a7e544e@syzkaller.appspotmail.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/000000000000e5560e05c3bd1d63@google.com
Link: https://lore.kernel.org/r/20210602113823.23777-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 20265d9a upstream.

Before this patch, in the unlikely event that gfs2_glock_dq encountered
a withdraw, it would do a wait_on_bit to wait for its journal to be
recovered, but it never released the glock's spin_lock, which caused a
scheduling-while-atomic error.

This patch unlocks the lockref spin_lock before waiting for recovery.

Fixes: 601ef0d5

 ("gfs2: Force withdraw to replay journals and wait for it to finish")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a2353e3b

 upstream.

This effectively changes collection_is_mt from
  contact ID in report->field
to
  (device is Win8 => collection is finger) && contact ID in report->field

Some devices erroneously report Pen for fingers, and Win8 stylus-on-touchscreen
devices report contact ID, but mark the accompanying touchscreen device's
collection correctly

Cc: stable@vger.kernel.org
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4b4f6cec upstream.

Commit 9d7b1866

 ("HID: magicmouse: add support for Apple Magic
Trackpad 2") added a sanity check for an Apple trackpad but returned
success instead of -ENODEV when the check failed. This means that the
remove callback will dereference the never-initialised driver data
pointer when the driver is later unbound (e.g. on USB disconnect).

Reported-by:  <syzbot+ee6f6e2e68886ca256a8@syzkaller.appspotmail.com>
Fixes: 9d7b1866

 ("HID: magicmouse: add support for Apple Magic Trackpad 2")
Cc: stable@vger.kernel.org      # 4.20
Cc: Claudio Mettler <claudio@ponyfleisch.ch>
Cc: Marek Wyborski <marek.wyborski@emwesoft.com>
Cc: Sean O'Brien <seobrien@chromium.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ca66a677 upstream.

For ELAN touchscreen, we found our boot code of IC was not flexible enough
to receive and handle this command.
Once the FW main code of our controller is crashed for some reason,
the controller could not be enumerated successfully to be recognized
by the system host. therefore, it lost touch functionality.

Add quirk for skip send power-on command after reset.
It will impact to ELAN touchscreen and touchpad on HID over I2C projects.

Fixes: 43b7029f

 ("HID: i2c-hid: Send power-on command after reset").

Cc: stable@vger.kernel.org
Signed-off-by: Johnny Chuang <johnny.chuang.emc@gmail.com>
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7f5d8666 upstream.

In case of caif_enroll_dev() fail, allocated
link_support won't be assigned to the corresponding
structure. So simply free allocated pointer in case
of error.

Fixes: 7ad65bf6

 ("caif: Add support for CAIF over CDC NCM USB interface")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b53558a9 upstream.

In case of caif_enroll_dev() fail, allocated
link_support won't be assigned to the corresponding
structure. So simply free allocated pointer in case
of error

Fixes: 7c18d220

 ("caif: Restructure how link caif link layer enroll")
Cc: stable@vger.kernel.org
Reported-and-tested-by:  <syzbot+7ec324747ce876a29db6@syzkaller.appspotmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a2805dca upstream.

caif_enroll_dev() can fail in some cases. Ingnoring
these cases can lead to memory leak due to not assigning
link_support pointer to anywhere.

Fixes: 7c18d220

 ("caif: Restructure how link caif link layer enroll")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bce130e7

 upstream.

Added cfserl_release() function.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bf7b042d upstream.

When removing single nodes, it's possible that that node's parent is an
empty intermediate node, in which case, it too should be removed.
Otherwise the trie fills up and never is fully emptied, leading to
gradual memory leaks over time for tries that are modified often. There
was originally code to do this, but was removed during refactoring in
2016 and never reworked. Now that we have proper parent pointers from
the previous commits, we can implement this properly.

In order to reduce branching and expensive comparisons, we want to keep
the double pointer for parent assignment (which lets us easily chain up
to the root), but we still need to actually get the parent's base
address. So encode the bit number into the last two bits of the pointer,
and pack and unpack it as needed. This is a little bit clumsy but is the
fastest and less memory wasteful of the compromises. Note that we align
the root struct here to a minimum of 4, because it's embedded into a
larger struct, and we're relying on having the bottom two bits for our
flag, which would only be 16-bit aligned on m68k.

The existing macro-based helpers were a bit unwieldy for adding the bit
packing to, so this commit replaces them with safer and clearer ordinary
functions.

We add a test to the randomized/fuzzer part of the selftests, to free
the randomized tries by-peer, refuzz it, and repeat, until it's supposed
to be empty, and then then see if that actually resulted in the whole
thing being emptied. That combined with kmemcheck should hopefully make
sure this commit is doing what it should. Along the way this resulted in
various other cleanups of the tests and fixes for recent graphviz.

Fixes: e7096c13

 ("net: WireGuard secure network tunnel")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dc680de2 upstream.

The previous commit moved from O(n) to O(1) for removal, but in the
process introduced an additional pointer member to a struct that
increased the size from 60 to 68 bytes, putting nodes in the 128-byte
slab. With deployed systems having as many as 2 million nodes, this
represents a significant doubling in memory usage (128 MiB -> 256 MiB).
Fix this by using our own kmem_cache, that's sized exactly right. This
also makes wireguard's memory usage more transparent in tools like
slabtop and /proc/slabinfo.

Fixes: e7096c13

 ("net: WireGuard secure network tunnel")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f634f418 upstream.

Previously, deleting peers would require traversing the entire trie in
order to rebalance nodes and safely free them. This meant that removing
1000 peers from a trie with a half million nodes would take an extremely
long time, during which we're holding the rtnl lock. Large-scale users
were reporting 200ms latencies added to the networking stack as a whole
every time their userspace software would queue up significant removals.
That's a serious situation.

This commit fixes that by maintaining a double pointer to the parent's
bit pointer for each node, and then using the already existing node list
belonging to each peer to go directly to the node, fix up its pointers,
and free it with RCU. This means removal is O(1) instead of O(n), and we
don't use gobs of stack.

The removal algorithm has the same downside as the code that it fixes:
it won't collapse needlessly long runs of fillers.  We can enhance that
in the future if it ever becomes a problem. This commit documents that
limitation with a TODO comment in code, a small but meaningful
improvement over the prior situation.

Currently the biggest flaw, which the next commit addresses, is that
because this increases the node size on 64-bit machines from 60 bytes to
68 bytes. 60 rounds up to 64, but 68 rounds up to 128. So we wind up
using twice as much memory per node, because of power-of-two
allocations, which is a big bummer. We'll need to figure something out
there.

Fixes: e7096c13

 ("net: WireGuard secure network tunnel")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 46cfe8ee upstream.

The randomized trie tests weren't initializing the dummy peer list head,
resulting in a NULL pointer dereference when used. Fix this by
initializing it in the randomized trie test, just like we do for the
static unit test.

While we're at it, all of the other strings like this have the word
"self-test", so add it to the missing place here.

Fixes: e7096c13

 ("net: WireGuard secure network tunnel")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>