1. 15 Dec, 2021 3 commits
    • Eric Dumazet's avatar
      net: linkwatch: be more careful about dev->linkwatch_dev_tracker · 123e495e
      Eric Dumazet authored
      Apparently a concurrent linkwatch_add_event() could
      run while we are in __linkwatch_run_queue().
      
      We need to free dev->linkwatch_dev_tracker tracker
      under lweventlist_lock protection to avoid this race.
      
      syzbot report:
      [   77.935949][ T3661] reference already released.
      [   77.941015][ T3661] allocated in:
      [   77.944482][ T3661]  linkwatch_fire_event+0x202/0x260
      [   77.950318][ T3661]  netif_carrier_on+0x9c/0x100
      [   77.955120][ T3661]  __ieee80211_sta_join_ibss+0xc52/0x1590
      [   77.960888][ T3661]  ieee80211_sta_create_ibss.cold+0xd2/0x11f
      [   77.966908][ T3661]  ieee80211_ibss_work.cold+0x30e/0x60f
      [   77.972483][ T3661]  ieee80211_iface_work+0xb70/0xd00
      [   77.977715][ T3661]  process_one_work+0x9ac/0x1680
      [   77.982671][ T3661]  worker_thread+0x652/0x11c0
      [   77.987371][ T3661]  kthread+0x405/0x4f0
      [   77.991465][ T3661]  ret_from_fork+0x1f/0x30
      [   77.995895][ T3661] freed in:
      [   77.999006][ T3661]  linkwatch_do_dev+0x96/0x160
      [   78.004014][ T3661]  __linkwatch_run_queue+0x233/0x6a0
      [   78.009496][ T3661]  linkwatch_event+0x4a/0x60
      [   78.014099][ T3661]  process_one_work+0x9ac/0x1680
      [   78.019034][ T3661]  worker_thread+0x652/0x11c0
      [   78.023719][ T3661]  kthread+0x405/0x4f0
      [   78.027810][ T3661]  ret_from_fork+0x1f/0x30
      [   78.042541][ T3661] ------------[ cut here ]------------
      [   78.048253][ T3661] WARNING: CPU: 0 PID: 3661 at lib/ref_tracker.c:120 ref_tracker_free.cold+0x110/0x14e
      [   78.062364][ T3661] Modules linked in:
      [   78.066424][ T3661] CPU: 0 PID: 3661 Comm: kworker/0:5 Not tainted 5.16.0-rc4-next-20211210-syzkaller #0
      [   78.076075][ T3661] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      [   78.090648][ T3661] Workqueue: events linkwatch_event
      [   78.095890][ T3661] RIP: 0010:ref_tracker_free.cold+0x110/0x14e
      [   78.102191][ T3661] Code: ea 03 48 c1 e0 2a 0f b6 04 02 84 c0 74 04 3c 03 7e 4c 8b 7b 18 e8 6b 54 e9 fa e8 26 4d 57 f8 4c 89 ee 48 89 ef e8 fb 33 36 00 <0f> 0b 41 bd ea ff ff ff e9 bd 60 e9 fa 4c 89 f7 e8 16 45 a2 f8 e9
      [   78.127211][ T3661] RSP: 0018:ffffc90002b5fb18 EFLAGS: 00010246
      [   78.133684][ T3661] RAX: 0000000000000000 RBX: ffff88807467f700 RCX: 0000000000000000
      [   78.141928][ T3661] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001
      [   78.150087][ T3661] RBP: ffff888057e105b8 R08: 0000000000000001 R09: ffffffff8ffa1967
      [   78.158211][ T3661] R10: 0000000000000001 R11: 0000000000000000 R12: 1ffff9200056bf65
      [   78.166204][ T3661] R13: 0000000000000292 R14: ffff88807467f718 R15: 00000000c0e0008c
      [   78.174321][ T3661] FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
      [   78.183310][ T3661] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [   78.190156][ T3661] CR2: 000000c000208800 CR3: 000000007f7b5000 CR4: 00000000003506f0
      [   78.198235][ T3661] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      [   78.206214][ T3661] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      [   78.214328][ T3661] Call Trace:
      [   78.217679][ T3661]  <TASK>
      [   78.220621][ T3661]  ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70
      [   78.226981][ T3661]  ? nlmsg_notify+0xbe/0x280
      [   78.231607][ T3661]  ? ref_tracker_dir_exit+0x330/0x330
      [   78.237654][ T3661]  ? linkwatch_do_dev+0x96/0x160
      [   78.242628][ T3661]  ? __linkwatch_run_queue+0x233/0x6a0
      [   78.248170][ T3661]  ? linkwatch_event+0x4a/0x60
      [   78.252946][ T3661]  ? process_one_work+0x9ac/0x1680
      [   78.258136][ T3661]  ? worker_thread+0x853/0x11c0
      [   78.263020][ T3661]  ? kthread+0x405/0x4f0
      [   78.267905][ T3661]  ? ret_from_fork+0x1f/0x30
      [   78.272670][ T3661]  ? netdev_state_change+0xa1/0x130
      [   78.278019][ T3661]  ? netdev_exit+0xd0/0xd0
      [   78.282466][ T3661]  ? dev_activate+0x420/0xa60
      [   78.287261][ T3661]  linkwatch_do_dev+0x96/0x160
      [   78.292043][ T3661]  __linkwatch_run_queue+0x233/0x6a0
      [   78.297505][ T3661]  ? linkwatch_do_dev+0x160/0x160
      [   78.302561][ T3661]  linkwatch_event+0x4a/0x60
      [   78.307225][ T3661]  process_one_work+0x9ac/0x1680
      [   78.312292][ T3661]  ? pwq_dec_nr_in_flight+0x2a0/0x2a0
      [   78.317757][ T3661]  ? rwlock_bug.part.0+0x90/0x90
      [   78.322726][ T3661]  ? _raw_spin_lock_irq+0x41/0x50
      [   78.327844][ T3661]  worker_thread+0x853/0x11c0
      [   78.332543][ T3661]  ? process_one_work+0x1680/0x1680
      [   78.338500][ T3661]  kthread+0x405/0x4f0
      [   78.342610][ T3661]  ? set_kthread_struct+0x130/0x130
      
      Fixes: 63f13937 ("net: linkwatch: add net device refcount tracker")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Link: https://lore.kernel.org/r/20211214051955.3569843-1-eric.dumazet@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      123e495e
    • Eric Dumazet's avatar
      mptcp: adjust to use netns refcount tracker · 1d2f3d3c
      Eric Dumazet authored
      MPTCP can change sk_net_refcnt after sock_create_kern() call.
      
      We need to change its corresponding get_net() to avoid
      a splat at release time, as in :
      
      refcount_t: decrement hit 0; leaking memory.
      WARNING: CPU: 0 PID: 3599 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
      Modules linked in:
      CPU: 1 PID: 3599 Comm: syz-fuzzer Not tainted 5.16.0-rc4-syzkaller #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
      Code: 1d b1 99 a1 09 31 ff 89 de e8 5d 3a 9c fd 84 db 75 e0 e8 74 36 9c fd 48 c7 c7 60 00 05 8a c6 05 91 99 a1 09 01 e8 cc 4b 27 05 <0f> 0b eb c4 e8 58 36 9c fd 0f b6 1d 80 99 a1 09 31 ff 89 de e8 28
      RSP: 0018:ffffc90001f5fab0 EFLAGS: 00010286
      RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
      RDX: ffff888021873a00 RSI: ffffffff815f1e28 RDI: fffff520003ebf48
      RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
      R10: ffffffff815ebbce R11: 0000000000000000 R12: 1ffff920003ebf5b
      R13: 00000000ffffffef R14: ffffffff8d2fcd94 R15: ffffc90001f5fd10
      FS:  000000c00008a090(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007f0a5b59e300 CR3: 000000001cbe6000 CR4: 00000000003506e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
       <TASK>
       __refcount_dec include/linux/refcount.h:344 [inline]
       refcount_dec include/linux/refcount.h:359 [inline]
       ref_tracker_free+0x4fe/0x610 lib/ref_tracker.c:101
       netns_tracker_free include/net/net_namespace.h:327 [inline]
       put_net_track include/net/net_namespace.h:341 [inline]
       __sk_destruct+0x4a6/0x920 net/core/sock.c:2042
       sk_destruct+0xbd/0xe0 net/core/sock.c:2058
       __sk_free+0xef/0x3d0 net/core/sock.c:2069
       sk_free+0x78/0xa0 net/core/sock.c:2080
       sock_put include/net/sock.h:1911 [inline]
       __mptcp_close_ssk+0x435/0x590 net/mptcp/protocol.c:2276
       __mptcp_destroy_sock+0x35f/0x830 net/mptcp/protocol.c:2702
       mptcp_close+0x5f8/0x7f0 net/mptcp/protocol.c:2750
       inet_release+0x12e/0x280 net/ipv4/af_inet.c:428
       inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:476
       __sock_release+0xcd/0x280 net/socket.c:649
       sock_close+0x18/0x20 net/socket.c:1314
       __fput+0x286/0x9f0 fs/file_table.c:280
       task_work_run+0xdd/0x1a0 kernel/task_work.c:164
       tracehook_notify_resume include/linux/tracehook.h:189 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
       exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
       __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
       syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
       do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x44/0xae
      
      Fixes: ffa84b5f ("net: add netns refcount tracker to struct sock")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Mat Martineau <mathew.j.martineau@linux.intel.com>
      Cc: Florian Westphal <fw@strlen.de>
      Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
      Reviewed-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
      Link: https://lore.kernel.org/r/20211214043208.3543046-1-eric.dumazet@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      1d2f3d3c
    • Eric Dumazet's avatar
      ipv6: use GFP_ATOMIC in rt6_probe() · 8b40a9d5
      Eric Dumazet authored
      syzbot reminded me that rt6_probe() can run from
      atomic contexts.
      
      stack backtrace:
      
      CPU: 1 PID: 7461 Comm: syz-executor.2 Not tainted 5.16.0-rc4-next-20211210-syzkaller #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       <IRQ>
       __dump_stack lib/dump_stack.c:88 [inline]
       dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
       print_usage_bug kernel/locking/lockdep.c:203 [inline]
       valid_state kernel/locking/lockdep.c:3945 [inline]
       mark_lock_irq kernel/locking/lockdep.c:4148 [inline]
       mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4605
       mark_usage kernel/locking/lockdep.c:4500 [inline]
       __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4981
       lock_acquire kernel/locking/lockdep.c:5639 [inline]
       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
       __fs_reclaim_acquire mm/page_alloc.c:4550 [inline]
       fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4564
       might_alloc include/linux/sched/mm.h:253 [inline]
       slab_pre_alloc_hook mm/slab.h:739 [inline]
       slab_alloc_node mm/slub.c:3145 [inline]
       slab_alloc mm/slub.c:3239 [inline]
       kmem_cache_alloc_trace+0x3b/0x2c0 mm/slub.c:3256
       kmalloc include/linux/slab.h:581 [inline]
       kzalloc include/linux/slab.h:715 [inline]
       ref_tracker_alloc+0xe1/0x430 lib/ref_tracker.c:74
       netdev_tracker_alloc include/linux/netdevice.h:3860 [inline]
       dev_hold_track include/linux/netdevice.h:3877 [inline]
       rt6_probe net/ipv6/route.c:661 [inline]
       find_match.part.0+0xac9/0xd00 net/ipv6/route.c:752
       find_match net/ipv6/route.c:825 [inline]
       __find_rr_leaf+0x17f/0xd20 net/ipv6/route.c:826
       find_rr_leaf net/ipv6/route.c:847 [inline]
       rt6_select net/ipv6/route.c:891 [inline]
       fib6_table_lookup+0x649/0xa20 net/ipv6/route.c:2185
       ip6_pol_route+0x1c5/0x11e0 net/ipv6/route.c:2221
       pol_lookup_func include/net/ip6_fib.h:580 [inline]
       fib6_rule_lookup+0x52a/0x6f0 net/ipv6/fib6_rules.c:120
       ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2629
       ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2642
       ip6_route_output include/net/ip6_route.h:98 [inline]
       ip6_dst_lookup_tail+0x5ab/0x1620 net/ipv6/ip6_output.c:1070
       ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200
       geneve_get_v6_dst+0x46f/0x9a0 drivers/net/geneve.c:858
       geneve6_xmit_skb drivers/net/geneve.c:991 [inline]
       geneve_xmit+0x520/0x3530 drivers/net/geneve.c:1074
       __netdev_start_xmit include/linux/netdevice.h:4685 [inline]
       netdev_start_xmit include/linux/netdevice.h:4699 [inline]
       xmit_one net/core/dev.c:3473 [inline]
       dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489
       __dev_queue_xmit+0x2983/0x3640 net/core/dev.c:4112
       neigh_resolve_output net/core/neighbour.c:1522 [inline]
       neigh_resolve_output+0x50e/0x820 net/core/neighbour.c:1502
       neigh_output include/net/neighbour.h:541 [inline]
       ip6_finish_output2+0x56e/0x14f0 net/ipv6/ip6_output.c:126
       __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
       __ip6_finish_output+0x61e/0xe80 net/ipv6/ip6_output.c:170
       ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201
       NF_HOOK_COND include/linux/netfilter.h:296 [inline]
       ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
       dst_output include/net/dst.h:451 [inline]
       NF_HOOK include/linux/netfilter.h:307 [inline]
       ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508
       ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702
       addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3898
       call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
       expire_timers kernel/time/timer.c:1466 [inline]
       __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
       __run_timers kernel/time/timer.c:1715 [inline]
       run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
       __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
       invoke_softirq kernel/softirq.c:432 [inline]
       __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
       sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
       </IRQ>
      
      Fixes: fb67510b ("ipv6: add net device refcount tracker to rt6_probe_deferred()")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Link: https://lore.kernel.org/r/20211214025806.3456382-1-eric.dumazet@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      8b40a9d5
  2. 14 Dec, 2021 14 commits
  3. 13 Dec, 2021 23 commits