• Maor Gottlieb's avatar
    RDMA/mlx5: Fix NULL pointer dereference in destroy_prefetch_work · 189277f3
    Maor Gottlieb authored
    q_deferred_work isn't initialized when creating an explicit ODP memory
    region. This can lead to a NULL pointer dereference when user performs
    asynchronous prefetch MR. Fix it by initializing q_deferred_work for
    explicit ODP.
    
      BUG: kernel NULL pointer dereference, address: 0000000000000000
      #PF: supervisor read access in kernel mode
      #PF: error_code(0x0000) - not-present page
      PGD 0 P4D 0
      Oops: 0000 [#1] SMP PTI
      CPU: 4 PID: 6074 Comm: kworker/u16:6 Not tainted 5.7.0-rc1-for-upstream-perf-2020-04-17_07-03-39-64 #1
      Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
      Workqueue: events_unbound mlx5_ib_prefetch_mr_work [mlx5_ib]
      RIP: 0010:__wake_up_common+0x49/0x120
      Code: 04 89 54 24 0c 89 4c 24 08 74 0a 41 f6 01 04 0f 85 8e 00 00 00 48 8b 47 08 48 83 e8 18 4c 8d 67 08 48 8d 50 18 49 39 d4 74 66 <48> 8b 70 18 31 db 4c 8d 7e e8 eb 17 49 8b 47 18 48 8d 50 e8 49 8d
      RSP: 0000:ffffc9000097bd88 EFLAGS: 00010082
      RAX: ffffffffffffffe8 RBX: ffff888454cd9f90 RCX: 0000000000000000
      RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff888454cd9f90
      RBP: ffffc9000097bdd0 R08: 0000000000000000 R09: ffffc9000097bdd0
      R10: 0000000000000000 R11: 0000000000000001 R12: ffff888454cd9f98
      R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
      FS:  0000000000000000(0000) GS:ffff88846fd00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 0000000000000000 CR3: 000000044c19e002 CR4: 0000000000760ee0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      PKRU: 55555554
      Call Trace:
       __wake_up_common_lock+0x7a/0xc0
       destroy_prefetch_work+0x5a/0x60 [mlx5_ib]
       mlx5_ib_prefetch_mr_work+0x64/0x80 [mlx5_ib]
       process_one_work+0x15b/0x360
       worker_thread+0x49/0x3d0
       kthread+0xf5/0x130
       ? rescuer_thread+0x310/0x310
       ? kthread_bind+0x10/0x10
       ret_from_fork+0x1f/0x30
    
    Fixes: de5ed007 ("IB/mlx5: Fix implicit ODP race")
    Cc: stable@vger.kernel.org
    Link: https://lore.kernel.org/r/20200521072504.567406-1-leon@kernel.orgSigned-off-by: default avatarMaor Gottlieb <maorg@mellanox.com>
    Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
    Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
    189277f3
mr.c 61.2 KB