RDMA/restrack: Don't rely on uninitialized variable in restrack_add flow
authorLeon Romanovsky <leonro@mellanox.com>
Thu, 15 Mar 2018 09:10:42 +0000 (11:10 +0200)
committerJason Gunthorpe <jgg@mellanox.com>
Fri, 16 Mar 2018 22:35:25 +0000 (16:35 -0600)
commit7d9a935e169b7e51a5f84caf8dfb02aad6206902
treec76901747ca316de883319925cdc4fa6aa0386dd
parent6d06c9aa3816c26144f54d18c5b63ba9ff026fb9
RDMA/restrack: Don't rely on uninitialized variable in restrack_add flow

The restrack code relies on the fact that object structures are zeroed at
the allocation stage, the mlx4 CQ wasn't allocated with kzalloc and it
caused to the following crash.

[  137.392209] general protection fault: 0000 [#1] SMP KASAN PTI
[  137.392972] CPU: 0 PID: 622 Comm: ibv_rc_pingpong Tainted: G        W        4.16.0-rc1-00099-g00313983cda6 #11
[  137.395079] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
[  137.396866] RIP: 0010:rdma_restrack_del+0xc8/0xf0
[  137.397762] RSP: 0018:ffff8801b54e7968 EFLAGS: 00010206
[  137.399008] RAX: 0000000000000000 RBX: ffff8801d8bcbae8 RCX: ffffffffb82314df
[  137.400055] RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: 70696b533d454741
[  137.401103] RBP: ffff8801d90c07a0 R08: ffff8801d8bcbb00 R09: 0000000000000000
[  137.402470] R10: 0000000000000001 R11: ffffed0036a9cf52 R12: ffff8801d90c0ad0
[  137.403318] R13: ffff8801d853fb20 R14: ffff8801d8bcbb28 R15: 0000000000000014
[  137.404736] FS:  00007fb415d43740(0000) GS:ffff8801e5c00000(0000) knlGS:0000000000000000
[  137.406074] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  137.407101] CR2: 00007fb41557df20 CR3: 00000001b580c001 CR4: 00000000003606b0
[  137.408308] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  137.409352] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  137.410385] Call Trace:
[  137.411058]  ib_destroy_cq+0x23/0x60
[  137.411460]  uverbs_free_cq+0x37/0xa0
[  137.412040]  remove_commit_idr_uobject+0x38/0xf0
[  137.413042]  _rdma_remove_commit_uobject+0x5c/0x160
[  137.413782]  ? lookup_get_idr_uobject+0x39/0x50
[  137.414737]  rdma_remove_commit_uobject+0x3b/0x70
[  137.415742]  ib_uverbs_destroy_cq+0x114/0x1d0
[  137.416260]  ? ib_uverbs_req_notify_cq+0x160/0x160
[  137.417073]  ? kernel_text_address+0x5c/0x90
[  137.417805]  ? __kernel_text_address+0xe/0x30
[  137.418766]  ? unwind_get_return_address+0x2f/0x50
[  137.419558]  ib_uverbs_write+0x453/0x6a0
[  137.420220]  ? show_ibdev+0x90/0x90
[  137.420653]  ? __kasan_slab_free+0x136/0x180
[  137.421155]  ? kmem_cache_free+0x78/0x1e0
[  137.422192]  ? remove_vma+0x83/0x90
[  137.422614]  ? do_munmap+0x447/0x6c0
[  137.423045]  ? vm_munmap+0xb0/0x100
[  137.423481]  ? SyS_munmap+0x1d/0x30
[  137.424120]  ? do_syscall_64+0xeb/0x250
[  137.424984]  ? entry_SYSCALL_64_after_hwframe+0x21/0x86
[  137.425611]  ? lru_add_drain_all+0x270/0x270
[  137.426116]  ? lru_add_drain_cpu+0xa3/0x170
[  137.426616]  ? lru_add_drain+0x11/0x20
[  137.427058]  ? free_pages_and_swap_cache+0xa6/0x120
[  137.427672]  ? tlb_flush_mmu_free+0x78/0x90
[  137.428168]  ? arch_tlb_finish_mmu+0x6d/0xb0
[  137.428680]  __vfs_write+0xc4/0x350
[  137.430917]  ? kernel_read+0xa0/0xa0
[  137.432758]  ? remove_vma+0x90/0x90
[  137.434781]  ? __kasan_slab_free+0x14b/0x180
[  137.437486]  ? remove_vma+0x83/0x90
[  137.439836]  ? kmem_cache_free+0x78/0x1e0
[  137.442195]  ? percpu_counter_add_batch+0x1d/0x90
[  137.444389]  vfs_write+0xf7/0x280
[  137.446030]  SyS_write+0xa1/0x120
[  137.447867]  ? SyS_read+0x120/0x120
[  137.449670]  ? mm_fault_error+0x180/0x180
[  137.451539]  ? _cond_resched+0x16/0x50
[  137.453697]  ? SyS_read+0x120/0x120
[  137.455883]  do_syscall_64+0xeb/0x250
[  137.457686]  entry_SYSCALL_64_after_hwframe+0x21/0x86
[  137.459595] RIP: 0033:0x7fb415637b94
[  137.461315] RSP: 002b:00007ffdebea7d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  137.463879] RAX: ffffffffffffffda RBX: 00005565022d1bd0 RCX: 00007fb415637b94
[  137.466519] RDX: 0000000000000018 RSI: 00007ffdebea7da0 RDI: 0000000000000003
[  137.469543] RBP: 00007ffdebea7d98 R08: 0000000000000000 R09: 00005565022d40c0
[  137.472479] R10: 00000000000009cf R11: 0000000000000246 R12: 00005565022d2520
[  137.475125] R13: 00000000000003e8 R14: 0000000000000000 R15: 00007ffdebea7fd0
[  137.477760] Code: f7 e8 dd 0d 0b ff 48 c7 43 40 00 00 00 00 48 89 df e8 0d 0b 0b ff 48 8d 7b 28 c6 03 00 e8 41 0d 0b ff 48 8b 7b 28 48 85 ff 74 06 <f0> ff 4f 48 74 10 5b 48 89 ef 5d 41 5c 41 5d 41 5e e9 32 b0 ee
[  137.483375] RIP: rdma_restrack_del+0xc8/0xf0 RSP: ffff8801b54e7968
[  137.486436] ---[ end trace 81835a1ea6722eed ]---
[  137.488566] Kernel panic - not syncing: Fatal exception
[  137.491162] Kernel Offset: 0x36000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Fixes: 00313983cda6 ("RDMA/nldev: provide detailed CM_ID information")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
drivers/infiniband/core/restrack.c