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  1. Mar 28, 2018
    • Eran Ben Elisha's avatar
      net/mlx4_en: Fix mixed PFC and Global pause user control requests · 6e8814ce
      Eran Ben Elisha authored
      
      
      Global pause and PFC configuration should be mutually exclusive (i.e. only
      one of them at most can be set). However, once PFC was turned off,
      driver automatically turned Global pause on. This is a bug.
      
      Fix the driver behaviour to turn off PFC/Global once the user turned the
      other on.
      
      This also fixed a weird behaviour that at a current time, the profile
      had both PFC and global pause configuration turned on, which is
      Hardware-wise impossible and caused returning false positive indication
      to query tools.
      
      In addition, fix error code when setting global pause or PFC to change
      metadata only upon successful change.
      
      Also, removed useless debug print.
      
      Fixes: af7d5185 ("net/mlx4_en: Add DCB PFC support through CEE netlink commands")
      Fixes: c27a02cd ("mlx4_en: Add driver for Mellanox ConnectX 10GbE NIC")
      Signed-off-by: default avatarEran Ben Elisha <eranbe@mellanox.com>
      Signed-off-by: default avatarTariq Toukan <tariqt@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6e8814ce
  2. Mar 27, 2018
  3. Mar 26, 2018
    • David S. Miller's avatar
      Merge tag 'wireless-drivers-for-davem-2018-03-24' of... · c87308b1
      David S. Miller authored
      Merge tag 'wireless-drivers-for-davem-2018-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers
      
      
      
      Kalle Valo says:
      
      ====================
      wireless-drivers fixes for 4.16
      
      Some fixes for 4.16, only for iwlwifi and brcmfmac this time. All
      pretty small.
      
      iwlwifi
      
      * fix an issue with the multicast queue
      
      * fix IGTK handling
      
      * fix some missing return value checks
      
      * add support for a HW workaround for issues on some platforms
      
      * a couple of fixes for channel-switch
      
      * a few fixes for the aggregation handling code
      
      brcmfmac
      
      * drop Inter-Access Point Protocol packets by default
      
      * fix check for ISO3166 regulatory code
      ====================
      
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c87308b1
    • Paolo Abeni's avatar
      ipv6: the entire IPv6 header chain must fit the first fragment · 10b8a3de
      Paolo Abeni authored
      
      
      While building ipv6 datagram we currently allow arbitrary large
      extheaders, even beyond pmtu size. The syzbot has found a way
      to exploit the above to trigger the following splat:
      
      kernel BUG at ./include/linux/skbuff.h:2073!
      invalid opcode: 0000 [#1] SMP KASAN
      Dumping ftrace buffer:
          (ftrace buffer empty)
      Modules linked in:
      CPU: 1 PID: 4230 Comm: syzkaller672661 Not tainted 4.16.0-rc2+ #326
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
      Google 01/01/2011
      RIP: 0010:__skb_pull include/linux/skbuff.h:2073 [inline]
      RIP: 0010:__ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636
      RSP: 0018:ffff8801bc18f0f0 EFLAGS: 00010293
      RAX: ffff8801b17400c0 RBX: 0000000000000738 RCX: ffffffff84f01828
      RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801b415ac18
      RBP: ffff8801bc18f360 R08: ffff8801b4576844 R09: 0000000000000000
      R10: ffff8801bc18f380 R11: ffffed00367aee4e R12: 00000000000000d6
      R13: ffff8801b415a740 R14: dffffc0000000000 R15: ffff8801b45767c0
      FS:  0000000001535880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 000000002000b000 CR3: 00000001b4123001 CR4: 00000000001606e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
        ip6_finish_skb include/net/ipv6.h:969 [inline]
        udp_v6_push_pending_frames+0x269/0x3b0 net/ipv6/udp.c:1073
        udpv6_sendmsg+0x2a96/0x3400 net/ipv6/udp.c:1343
        inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
        sock_sendmsg_nosec net/socket.c:630 [inline]
        sock_sendmsg+0xca/0x110 net/socket.c:640
        ___sys_sendmsg+0x320/0x8b0 net/socket.c:2046
        __sys_sendmmsg+0x1ee/0x620 net/socket.c:2136
        SYSC_sendmmsg net/socket.c:2167 [inline]
        SyS_sendmmsg+0x35/0x60 net/socket.c:2162
        do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
        entry_SYSCALL_64_after_hwframe+0x42/0xb7
      RIP: 0033:0x4404c9
      RSP: 002b:00007ffdce35f948 EFLAGS: 00000217 ORIG_RAX: 0000000000000133
      RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404c9
      RDX: 0000000000000003 RSI: 0000000020001f00 RDI: 0000000000000003
      RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
      R10: 0000000020000080 R11: 0000000000000217 R12: 0000000000401df0
      R13: 0000000000401e80 R14: 0000000000000000 R15: 0000000000000000
      Code: ff e8 1d 5e b9 fc e9 15 e9 ff ff e8 13 5e b9 fc e9 44 e8 ff ff e8 29
      5e b9 fc e9 c0 e6 ff ff e8 3f f3 80 fc 0f 0b e8 38 f3 80 fc <0f> 0b 49 8d
      87 80 00 00 00 4d 8d 87 84 00 00 00 48 89 85 20 fe
      RIP: __skb_pull include/linux/skbuff.h:2073 [inline] RSP: ffff8801bc18f0f0
      RIP: __ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636 RSP:
      ffff8801bc18f0f0
      
      As stated by RFC 7112 section 5:
      
         When a host fragments an IPv6 datagram, it MUST include the entire
         IPv6 Header Chain in the First Fragment.
      
      So this patch addresses the issue dropping datagrams with excessive
      extheader length. It also updates the error path to report to the
      calling socket nonnegative pmtu values.
      
      The issue apparently predates git history.
      
      v1 -> v2: cleanup error path, as per Eric's suggestion
      
      Fixes: 1da177e4 ("Linux-2.6.12-rc2")
      Reported-by: default avatar <syzbot+91e6f9932ff122fa4410@syzkaller.appspotmail.com>
      Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      10b8a3de
    • Alexander Potapenko's avatar
      netlink: make sure nladdr has correct size in netlink_connect() · 78802879
      Alexander Potapenko authored
      
      
      KMSAN reports use of uninitialized memory in the case when |alen| is
      smaller than sizeof(struct sockaddr_nl), and therefore |nladdr| isn't
      fully copied from the userspace.
      
      Signed-off-by: default avatarAlexander Potapenko <glider@google.com>
      Fixes: 1da177e4 ("Linux-2.6.12-rc2")
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      78802879
    • Raghuram Chary J's avatar
      lan78xx: Set ASD in MAC_CR when EEE is enabled. · e69647a1
      Raghuram Chary J authored
      
      
      Description:
      EEE does not work with lan7800 when AutoSpeed is not set.
      (This can happen when EEPROM is not populated or configured incorrectly)
      
      Root-Cause:
      When EEE is enabled, the mac config register ASD is not set
      i.e. in default state, causing EEE fail.
      
      Fix:
      Set the register when eeprom is not present.
      
      Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
      Signed-off-by: default avatarRaghuram Chary J <raghuramchary.jallipalli@microchip.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e69647a1
    • Hans Wippel's avatar
      net/ipv4: disable SMC TCP option with SYN Cookies · bc58a1ba
      Hans Wippel authored
      
      
      Currently, the SMC experimental TCP option in a SYN packet is lost on
      the server side when SYN Cookies are active. However, the corresponding
      SYNACK sent back to the client contains the SMC option. This causes an
      inconsistent view of the SMC capabilities on the client and server.
      
      This patch disables the SMC option in the SYNACK when SYN Cookies are
      active to avoid this issue.
      
      Fixes: 60e2a778 ("tcp: TCP experimental option for SMC")
      Signed-off-by: default avatarHans Wippel <hwippel@linux.vnet.ibm.com>
      Signed-off-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bc58a1ba
  4. Mar 25, 2018
    • David S. Miller's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf · b9ee96b4
      David S. Miller authored
      
      
      Pablo Neira Ayuso says:
      
      ====================
      Netfilter fixes for net
      
      The following patchset contains Netfilter fixes for your net tree,
      they are:
      
      1) Don't pick fixed hash implementation for NFT_SET_EVAL sets, otherwise
         userspace hits EOPNOTSUPP with valid rules using the meter statement,
         from Florian Westphal.
      
      2) If you send a batch that flushes the existing ruleset (that contains
         a NAT chain) and the new ruleset definition comes with a new NAT
         chain, don't bogusly hit EBUSY. Also from Florian.
      
      3) Missing netlink policy attribute validation, from Florian.
      
      4) Detach conntrack template from skbuff if IP_NODEFRAG is set on,
         from Paolo Abeni.
      
      5) Cache device names in flowtable object, otherwise we may end up
         walking over devices going aways given no rtnl_lock is held.
      
      6) Fix incorrect net_device ingress with ingress hooks.
      
      7) Fix crash when trying to read more data than available in UDP
         packets from the nf_socket infrastructure, from Subash.
      ====================
      
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b9ee96b4
    • Subash Abhinov Kasiviswanathan's avatar
      netfilter: nf_socket: Fix out of bounds access in nf_sk_lookup_slow_v{4,6} · 32c1733f
      Subash Abhinov Kasiviswanathan authored
      
      
      skb_header_pointer will copy data into a buffer if data is non linear,
      otherwise it will return a pointer in the linear section of the data.
      nf_sk_lookup_slow_v{4,6} always copies data of size udphdr but later
      accesses memory within the size of tcphdr (th->doff) in case of TCP
      packets. This causes a crash when running with KASAN with the following
      call stack -
      
      BUG: KASAN: stack-out-of-bounds in xt_socket_lookup_slow_v4+0x524/0x718
      net/netfilter/xt_socket.c:178
      Read of size 2 at addr ffffffe3d417a87c by task syz-executor/28971
      CPU: 2 PID: 28971 Comm: syz-executor Tainted: G    B   W  O    4.9.65+ #1
      Call trace:
      [<ffffff9467e8d390>] dump_backtrace+0x0/0x428 arch/arm64/kernel/traps.c:76
      [<ffffff9467e8d7e0>] show_stack+0x28/0x38 arch/arm64/kernel/traps.c:226
      [<ffffff946842d9b8>] __dump_stack lib/dump_stack.c:15 [inline]
      [<ffffff946842d9b8>] dump_stack+0xd4/0x124 lib/dump_stack.c:51
      [<ffffff946811d4b0>] print_address_description+0x68/0x258 mm/kasan/report.c:248
      [<ffffff946811d8c8>] kasan_report_error mm/kasan/report.c:347 [inline]
      [<ffffff946811d8c8>] kasan_report.part.2+0x228/0x2f0 mm/kasan/report.c:371
      [<ffffff946811df44>] kasan_report+0x5c/0x70 mm/kasan/report.c:372
      [<ffffff946811bebc>] check_memory_region_inline mm/kasan/kasan.c:308 [inline]
      [<ffffff946811bebc>] __asan_load2+0x84/0x98 mm/kasan/kasan.c:739
      [<ffffff94694d6f04>] __tcp_hdrlen include/linux/tcp.h:35 [inline]
      [<ffffff94694d6f04>] xt_socket_lookup_slow_v4+0x524/0x718 net/netfilter/xt_socket.c:178
      
      Fix this by copying data into appropriate size headers based on protocol.
      
      Fixes: a583636a ("inet: refactor inet[6]_lookup functions to take skb")
      Signed-off-by: default avatarTejaswi Tanikella <tejaswit@codeaurora.org>
      Signed-off-by: default avatarSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
      Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
      32c1733f
  5. Mar 24, 2018
    • Linus Lüssing's avatar
      batman-adv: fix packet loss for broadcasted DHCP packets to a server · a752c0a4
      Linus Lüssing authored
      
      
      DHCP connectivity issues can currently occur if the following conditions
      are met:
      
      1) A DHCP packet from a client to a server
      2) This packet has a multicast destination
      3) This destination has a matching entry in the translation table
         (FF:FF:FF:FF:FF:FF for IPv4, 33:33:00:01:00:02/33:33:00:01:00:03
          for IPv6)
      4) The orig-node determined by TT for the multicast destination
         does not match the orig-node determined by best-gateway-selection
      
      In this case the DHCP packet will be dropped.
      
      The "gateway-out-of-range" check is supposed to only be applied to
      unicasted DHCP packets to a specific DHCP server.
      
      In that case dropping the the unicasted frame forces the client to
      retry via a broadcasted one, but now directed to the new best
      gateway.
      
      A DHCP packet with broadcast/multicast destination is already ensured to
      always be delivered to the best gateway. Dropping a multicasted
      DHCP packet here will only prevent completing DHCP as there is no
      other fallback.
      
      So far, it seems the unicast check was implicitly performed by
      expecting the batadv_transtable_search() to return NULL for multicast
      destinations. However, a multicast address could have always ended up in
      the translation table and in fact is now common.
      
      To fix this potential loss of a DHCP client-to-server packet to a
      multicast address this patch adds an explicit multicast destination
      check to reliably bail out of the gateway-out-of-range check for such
      destinations.
      
      The issue and fix were tested in the following three node setup:
      
      - Line topology, A-B-C
      - A: gateway client, DHCP client
      - B: gateway server, hop-penalty increased: 30->60, DHCP server
      - C: gateway server, code modifications to announce FF:FF:FF:FF:FF:FF
      
      Without this patch, A would never transmit its DHCP Discover packet
      due to an always "out-of-range" condition. With this patch,
      a full DHCP handshake between A and B was possible again.
      
      Fixes: be7af5cf ("batman-adv: refactoring gateway handling code")
      Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
      Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
      a752c0a4
    • Linus Lüssing's avatar
      batman-adv: fix multicast-via-unicast transmission with AP isolation · f8fb3419
      Linus Lüssing authored
      
      
      For multicast frames AP isolation is only supposed to be checked on
      the receiving nodes and never on the originating one.
      
      Furthermore, the isolation or wifi flag bits should only be intepreted
      as such for unicast and never multicast TT entries.
      
      By injecting flags to the multicast TT entry claimed by a single
      target node it was verified in tests that this multicast address
      becomes unreachable, leading to packet loss.
      
      Omitting the "src" parameter to the batadv_transtable_search() call
      successfully skipped the AP isolation check and made the target
      reachable again.
      
      Fixes: 1d8ab8d3 ("batman-adv: Modified forwarding behaviour for multicast packets")
      Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
      Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
      f8fb3419
    • Eric Dumazet's avatar
      ipv6: fix possible deadlock in rt6_age_examine_exception() · 1bfa26ff
      Eric Dumazet authored
      
      
      syzbot reported a LOCKDEP splat [1] in rt6_age_examine_exception()
      
      rt6_age_examine_exception() is called while rt6_exception_lock is held.
      This lock is the lower one in the lock hierarchy, thus we can not
      call dst_neigh_lookup() function, as it can fallback to neigh_create()
      
      We should instead do a pure RCU lookup. As a bonus we avoid
      a pair of atomic operations on neigh refcount.
      
      [1]
      
      WARNING: possible circular locking dependency detected
      4.16.0-rc4+ #277 Not tainted
      
      syz-executor7/4015 is trying to acquire lock:
       (&ndev->lock){++--}, at: [<00000000416dce19>] __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
      
      but task is already holding lock:
       (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #3 (&tbl->lock){++-.}:
             __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
             _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
             __neigh_create+0x87e/0x1d90 net/core/neighbour.c:528
             neigh_create include/net/neighbour.h:315 [inline]
             ip6_neigh_lookup+0x9a7/0xba0 net/ipv6/route.c:228
             dst_neigh_lookup include/net/dst.h:405 [inline]
             rt6_age_examine_exception net/ipv6/route.c:1609 [inline]
             rt6_age_exceptions+0x381/0x660 net/ipv6/route.c:1645
             fib6_age+0xfb/0x140 net/ipv6/ip6_fib.c:2033
             fib6_clean_node+0x389/0x580 net/ipv6/ip6_fib.c:1919
             fib6_walk_continue+0x46c/0x8a0 net/ipv6/ip6_fib.c:1845
             fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1893
             fib6_clean_tree+0x1e6/0x340 net/ipv6/ip6_fib.c:1970
             __fib6_clean_all+0x1f4/0x3a0 net/ipv6/ip6_fib.c:1986
             fib6_clean_all net/ipv6/ip6_fib.c:1997 [inline]
             fib6_run_gc+0x16b/0x3c0 net/ipv6/ip6_fib.c:2053
             ndisc_netdev_event+0x3c2/0x4a0 net/ipv6/ndisc.c:1781
             notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
             __raw_notifier_call_chain kernel/notifier.c:394 [inline]
             raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
             call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
             call_netdevice_notifiers net/core/dev.c:1725 [inline]
             __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
             dev_change_flags+0xf5/0x140 net/core/dev.c:6994
             devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
             inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
             sock_do_ioctl+0xef/0x390 net/socket.c:957
             sock_ioctl+0x36b/0x610 net/socket.c:1081
             vfs_ioctl fs/ioctl.c:46 [inline]
             do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
             SYSC_ioctl fs/ioctl.c:701 [inline]
             SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
             do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
             entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      -> #2 (rt6_exception_lock){+.-.}:
             __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
             _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
             spin_lock_bh include/linux/spinlock.h:315 [inline]
             rt6_flush_exceptions+0x21/0x210 net/ipv6/route.c:1367
             fib6_del_route net/ipv6/ip6_fib.c:1677 [inline]
             fib6_del+0x624/0x12c0 net/ipv6/ip6_fib.c:1761
             __ip6_del_rt+0xc7/0x120 net/ipv6/route.c:2980
             ip6_del_rt+0x132/0x1a0 net/ipv6/route.c:2993
             __ipv6_dev_ac_dec+0x3b1/0x600 net/ipv6/anycast.c:332
             ipv6_dev_ac_dec net/ipv6/anycast.c:345 [inline]
             ipv6_sock_ac_close+0x2b4/0x3e0 net/ipv6/anycast.c:200
             inet6_release+0x48/0x70 net/ipv6/af_inet6.c:433
             sock_release+0x8d/0x1e0 net/socket.c:594
             sock_close+0x16/0x20 net/socket.c:1149
             __fput+0x327/0x7e0 fs/file_table.c:209
             ____fput+0x15/0x20 fs/file_table.c:243
             task_work_run+0x199/0x270 kernel/task_work.c:113
             exit_task_work include/linux/task_work.h:22 [inline]
             do_exit+0x9bb/0x1ad0 kernel/exit.c:865
             do_group_exit+0x149/0x400 kernel/exit.c:968
             get_signal+0x73a/0x16d0 kernel/signal.c:2469
             do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
             exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
             prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
             syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
             do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
             entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      -> #1 (&(&tb->tb6_lock)->rlock){+.-.}:
             __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
             _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
             spin_lock_bh include/linux/spinlock.h:315 [inline]
             __ip6_ins_rt+0x56/0x90 net/ipv6/route.c:1007
             ip6_route_add+0x141/0x190 net/ipv6/route.c:2955
             addrconf_prefix_route+0x44f/0x620 net/ipv6/addrconf.c:2359
             fixup_permanent_addr net/ipv6/addrconf.c:3368 [inline]
             addrconf_permanent_addr net/ipv6/addrconf.c:3391 [inline]
             addrconf_notify+0x1ad2/0x2310 net/ipv6/addrconf.c:3460
             notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
             __raw_notifier_call_chain kernel/notifier.c:394 [inline]
             raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
             call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
             call_netdevice_notifiers net/core/dev.c:1725 [inline]
             __dev_notify_flags+0x15d/0x430 net/core/dev.c:6958
             dev_change_flags+0xf5/0x140 net/core/dev.c:6994
             do_setlink+0xa22/0x3bb0 net/core/rtnetlink.c:2357
             rtnl_newlink+0xf37/0x1a50 net/core/rtnetlink.c:2965
             rtnetlink_rcv_msg+0x57f/0xb10 net/core/rtnetlink.c:4641
             netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2444
             rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4659
             netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
             netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
             netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
             sock_sendmsg_nosec net/socket.c:629 [inline]
             sock_sendmsg+0xca/0x110 net/socket.c:639
             ___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
             __sys_sendmsg+0xe5/0x210 net/socket.c:2081
             SYSC_sendmsg net/socket.c:2092 [inline]
             SyS_sendmsg+0x2d/0x50 net/socket.c:2088
             do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
             entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      -> #0 (&ndev->lock){++--}:
             lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
             __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
             _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
             __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
             ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
             pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
             pneigh_ifdown net/core/neighbour.c:695 [inline]
             neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
             rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
             addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
             addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
             notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
             __raw_notifier_call_chain kernel/notifier.c:394 [inline]
             raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
             call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
             call_netdevice_notifiers net/core/dev.c:1725 [inline]
             __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
             dev_change_flags+0xf5/0x140 net/core/dev.c:6994
             devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
             inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
             packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
             sock_do_ioctl+0xef/0x390 net/socket.c:957
             sock_ioctl+0x36b/0x610 net/socket.c:1081
             vfs_ioctl fs/ioctl.c:46 [inline]
             do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
             SYSC_ioctl fs/ioctl.c:701 [inline]
             SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
             do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
             entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      other info that might help us debug this:
      
      Chain exists of:
        &ndev->lock --> rt6_exception_lock --> &tbl->lock
      
       Possible unsafe locking scenario:
      
             CPU0                    CPU1
             ----                    ----
        lock(&tbl->lock);
                                     lock(rt6_exception_lock);
                                     lock(&tbl->lock);
        lock(&ndev->lock);
      
       *** DEADLOCK ***
      
      2 locks held by syz-executor7/4015:
       #0:  (rtnl_mutex){+.+.}, at: [<00000000a2f16daa>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
       #1:  (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292
      
      stack backtrace:
      CPU: 0 PID: 4015 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #277
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:17 [inline]
       dump_stack+0x194/0x24d lib/dump_stack.c:53
       print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223
       check_prev_add kernel/locking/lockdep.c:1863 [inline]
       check_prevs_add kernel/locking/lockdep.c:1976 [inline]
       validate_chain kernel/locking/lockdep.c:2417 [inline]
       __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
       _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
       __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
       ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
       pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
       pneigh_ifdown net/core/neighbour.c:695 [inline]
       neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
       rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
       addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
       addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
       inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
       packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
       sock_do_ioctl+0xef/0x390 net/socket.c:957
       sock_ioctl+0x36b/0x610 net/socket.c:1081
       vfs_ioctl fs/ioctl.c:46 [inline]
       do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7
      
      Fixes: c757faa8 ("ipv6: prepare fib6_age() for exception table")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Wei Wang <weiwan@google.com>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarWei Wang <weiwan@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1bfa26ff