smb: smbdirect: free completion queues with ib_free_cq()

smbdirect_connection_destroy_qp() creates the send and receive completion
queues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an
internal completion handler that runs ib_cq_poll_work() on a workqueue.
Tearing those CQs down with ib_destroy_cq() frees them without first
cancelling that poll work.

If the provider posts a completion late -- for example Soft-RoCE (rxe)
posting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the
handler re-queues ib_cq_poll_work() on the already-freed CQ, and a
follow-on access faults in rxe_req_notify_cq().

Use ib_free_cq(), which cancel_work_sync()es the poll work before freeing
the CQ, so no completion handler can run against a freed queue.

[ 1236.599526] ==================================================================
[ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0
[ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82
[ 1236.609017]
[ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy)
[ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work
[ 1236.609525] Call Trace:
[ 1236.609536]  <TASK>
[ 1236.609545]  __dump_stack+0x21/0x60
[ 1236.609562]  dump_stack_lvl+0xc2/0x100
[ 1236.609573]  print_address_description+0x77/0x200
[ 1236.609587]  ? ib_cq_poll_work+0xd0/0x1a0
[ 1236.609597]  print_report+0x58/0x70
[ 1236.609607]  kasan_report+0x117/0x150
[ 1236.609623]  ? ib_cq_poll_work+0xd0/0x1a0
[ 1236.609636]  ? process_scheduled_works+0x954/0x1600
[ 1236.609650]  ib_cq_poll_work+0xd0/0x1a0
[ 1236.609662]  ? process_scheduled_works+0x954/0x1600
[ 1236.609674]  process_scheduled_works+0xc22/0x1600
[ 1236.609698]  ? __pfx_process_scheduled_works+0x10/0x10
[ 1236.609713]  ? __pfx_assign_work+0x10/0x10
[ 1236.609726]  ? lock_is_held_type+0x7b/0x110
[ 1236.609741]  worker_thread+0x975/0xee0
[ 1236.609757]  ? __pfx_do_raw_spin_lock+0x10/0x10
[ 1236.609775]  ? __kthread_parkme+0x21e/0x260
[ 1236.609789]  kthread+0x3a6/0x490
[ 1236.609800]  ? __pfx_worker_thread+0x10/0x10
[ 1236.609809]  ? __pfx_kthread+0x10/0x10
[ 1236.609820]  ret_from_fork+0x55a/0xa20
[ 1236.609835]  ? __pfx_ret_from_fork+0x10/0x10
[ 1236.609850]  ? __pfx_kthread+0x10/0x10
[ 1236.609861]  ret_from_fork_asm+0x1a/0x30
[ 1236.609880]  </TASK>
[ 1236.609886]
[ 1236.661292] Allocated by task 5076:
[ 1236.662640]  kasan_save_track+0x3e/0x80
[ 1236.663842]  __kasan_kmalloc+0x72/0x90
[ 1236.664763]  __kmalloc_noprof+0x2b0/0x5d0
[ 1236.665356]  __ib_alloc_cq+0x284/0x1000
[ 1236.666573]  __ib_alloc_cq_any+0x23e/0x340
[ 1236.668654]  smbdirect_connection_create_qp+0x6f7/0x1070
[ 1236.669757]  smbdirect_accept_connect_request+0x500/0x1ca0
[ 1236.672625]  smbdirect_listen_rdma_event_handler+0x1655/0x1c50
[ 1236.673930]  cma_listen_handler+0x1bf/0x260
[ 1236.674923]  cma_cm_event_handler+0x128/0x380
[ 1236.676926]  cma_ib_req_handler+0x2d3d/0x4de0
[ 1236.678368]  cm_process_work+0xb0/0x530
[ 1236.680454]  cm_queue_work_unlock+0xb1/0x230
[ 1236.681673]  cm_work_handler+0x969f/0xdca0
[ 1236.682704]  process_scheduled_works+0xc22/0x1600
[ 1236.683447]  worker_thread+0x975/0xee0
[ 1236.685901]  kthread+0x3a6/0x490
[ 1236.688164]  ret_from_fork+0x55a/0xa20
[ 1236.689522]  ret_from_fork_asm+0x1a/0x30
[ 1236.690073]
[ 1236.690378] Freed by task 5137:
[ 1236.692242]  kasan_save_track+0x3e/0x80
[ 1236.694272]  kasan_save_free_info+0x40/0x50
[ 1236.695514]  __kasan_slab_free+0x3a/0x60
[ 1236.696773]  kfree+0x14e/0x4e0
[ 1236.697216]  ib_destroy_cq_user+0x18d/0x250
[ 1236.699817]  smbdirect_connection_destroy_qp+0xf2/0x280
[ 1236.702115]  smbdirect_socket_destroy_sync+0x1607/0x2720
[ 1236.704062]  smbdirect_socket_release+0x140/0x280
[ 1236.705286]  smb_direct_free_transport+0x3b/0x90
[ 1236.707241]  __ksmbd_conn_release_work+0x99/0xf0
[ 1236.709287]  process_scheduled_works+0xc22/0x1600
[ 1236.710763]  worker_thread+0x975/0xee0
[ 1236.711262]  kthread+0x3a6/0x490
[ 1236.711720]  ret_from_fork+0x55a/0xa20
[ 1236.712232]  ret_from_fork_asm+0x1a/0x30
[ 1236.712762]
[ 1236.712992] Last potentially related work creation:
[ 1236.715157]  kasan_save_stack+0x3e/0x60
[ 1236.716993]  kasan_record_aux_stack+0x99/0xb0
[ 1236.718864]  insert_work+0xb2/0x4a0
[ 1236.720916]  __queue_work+0xebb/0x1260
[ 1236.722397]  queue_work_on+0x23b/0x350
[ 1236.723809]  ib_cq_completion_workqueue+0xac/0x160
[ 1236.724895]  rxe_cq_post+0x433/0x7c0
[ 1236.726273]  rxe_receiver+0xa41/0xd0d0
[ 1236.727754]  do_work+0x272/0x860
[ 1236.728896]  process_scheduled_works+0xc22/0x1600
[ 1236.730026]  worker_thread+0x975/0xee0
[ 1236.731499]  kthread+0x3a6/0x490
[ 1236.732132]  ret_from_fork+0x55a/0xa20
[ 1236.733171]  ret_from_fork_asm+0x1a/0x30
[ 1236.734224]
[ 1236.734871] Second to last potentially related work creation:
[ 1236.736001]  kasan_save_stack+0x3e/0x60
[ 1236.737161]  kasan_record_aux_stack+0x99/0xb0
[ 1236.739074]  insert_work+0xb2/0x4a0
[ 1236.740414]  __queue_work+0xebb/0x1260
[ 1236.740932]  queue_work_on+0x23b/0x350
[ 1236.741849]  ib_cq_completion_workqueue+0xac/0x160
[ 1236.744099]  rxe_cq_post+0x433/0x7c0
[ 1236.745514]  rxe_receiver+0xa41/0xd0d0
[ 1236.746091]  do_work+0x272/0x860
[ 1236.747187]  process_scheduled_works+0xc22/0x1600
[ 1236.749060]  worker_thread+0x975/0xee0
[ 1236.750224]  kthread+0x3a6/0x490
[ 1236.751480]  ret_from_fork+0x55a/0xa20
[ 1236.751989]  ret_from_fork_asm+0x1a/0x30
[ 1236.752974]
[ 1236.753627] The buggy address belongs to the object at ffff888111865800
[ 1236.753627]  which belongs to the cache kmalloc-1k of size 1024
[ 1236.757729] The buggy address is located 0 bytes inside of
[ 1236.757729]  freed 1024-byte region [ffff888111865800, ffff888111865c00)
[ 1236.760816]
[ 1236.761373] The buggy address belongs to the physical page:
[ 1236.762599] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111860
[ 1236.764306] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 1236.765281] flags: 0x100000000000040(head|node=0|zone=2)
[ 1236.765979] page_type: f5(slab)
[ 1236.766410] raw: 0100000000000040 ffff8881000430c0 ffffea0004a7e210 ffffea0004586210
[ 1236.770418] raw: 0000000000000000 00000000000a000a 00000000f5000000 0000000000000000
[ 1236.775899] head: 0100000000000040 ffff8881000430c0 ffffea0004a7e210 ffffea0004586210
[ 1236.782823] head: 0000000000000000 00000000000a000a 00000000f5000000 0000000000000000
[ 1236.786239] head: 0100000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
[ 1236.790658] head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[ 1236.794132] page dumped because: kasan: bad access detected
[ 1236.798301]
[ 1236.799640] Memory state around the buggy address:
[ 1236.802028]  ffff888111865700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1236.806254]  ffff888111865780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1236.809036] >ffff888111865800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1236.813968]                    ^
[ 1236.816416]  ffff888111865880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1236.819454]  ffff888111865900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1236.823143] ==================================================================
[ 1236.830365] Disabling lock debugging due to kernel taint
[ 1236.831136] BUG: unable to handle page fault for address: ffffc90006dc8080
[ 1236.838157] #PF: supervisor read access in kernel mode
[ 1236.843686] #PF: error_code(0x0000) - not-present page
[ 1236.849393] PGD 100000067 P4D 100000067 PUD 100366067 PMD 12913e067 PTE 0
[ 1236.854156] Oops: Oops: 0000 [#1] SMP KASAN NOPTI
[ 1236.857893] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Tainted: G    B               7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy)
[ 1236.860893] ksmbd: smb_direct: smbdirect_connection_recv_io_refill() failed -ECONNRESET
[ 1236.864209] Tainted: [B]=BAD_PAGE
[ 1236.864220] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
[ 1236.864233] Workqueue: ib-comp-wq ib_cq_poll_work
[ 1236.878314] RIP: 0010:rxe_req_notify_cq+0x13a/0x350
[ 1236.881683] Code: 20 87 fd 4c 89 fe 48 ba 00 00 00 00 00 fc ff df 4c 8b 3e 49 83 ef 80 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 9b 01 00 00 <45> 8b 2f 41 80 3c 16 00 74 18 49 89 f6 48 89 f7 e8 71 20 87 fd 4c
[ 1236.886819] ksmbd: smb_direct: smbdirect_connection_recv_io_refill() failed -ECONNRESET
[ 1236.890671] RSP: 0018:ffff88810222f920 EFLAGS: 00010046
[ 1236.890705] RAX: 0000000000000000 RBX: ffff88810222f920 RCX: ffffffff84c92863
[ 1236.901613] RDX: dffffc0000000000 RSI: ffff888120456d48 RDI: ffff888120456d48
[ 1236.903979] RBP: ffff88810222fa20 R08: 0000000000000003 R09: 0000000000000004
[ 1236.908958] R10: dffffc0000000000 R11: ffffed1020445f10 R12: ffff888120456d40
[ 1236.914473] R13: dffffc0000000000 R14: 1ffff1102408ada9 R15: ffffc90006dc8080
[ 1236.918946] FS:  0000000000000000(0000) GS:ffff88842600d000(0000) knlGS:0000000000000000
[ 1236.921600] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1236.925779] CR2: ffffc90006dc8080 CR3: 000000012b35f003 CR4: 0000000000f72ef0
[ 1236.926809] ksmbd: smb_direct: smbdirect_connection_recv_io_refill() failed -ECONNRESET
[ 1236.928302] PKRU: 55555554
[ 1236.928328] Call Trace:
[ 1236.928338]  <TASK>
[ 1236.928352]  ? ib_cq_poll_work+0xd0/0x1a0
[ 1236.928374]  ? __pfx_rxe_req_notify_cq+0x10/0x10
[ 1236.941601]  ? ib_cq_poll_work+0xd0/0x1a0
[ 1236.943306]  ib_cq_poll_work+0xfe/0x1a0
[ 1236.943961]  ? process_scheduled_works+0x954/0x1600
[ 1236.947036]  process_scheduled_works+0xc22/0x1600
[ 1236.951626]  ? __pfx_process_scheduled_works+0x10/0x10
[ 1236.954316]  ? __pfx_assign_work+0x10/0x10
[ 1236.958110]  ? lock_is_held_type+0x7b/0x110
[ 1236.960042]  worker_thread+0x975/0xee0
[ 1236.962668]  ? __pfx_do_raw_spin_lock+0x10/0x10
[ 1236.965334]  ? __kthread_parkme+0x21e/0x260
[ 1236.966058]  kthread+0x3a6/0x490
[ 1236.968115]  ? __pfx_worker_thread+0x10/0x10
[ 1236.971020]  ? __pfx_kthread+0x10/0x10
[ 1236.974488]  ret_from_fork+0x55a/0xa20
[ 1236.977419]  ? __pfx_ret_from_fork+0x10/0x10
[ 1236.979846]  ? __pfx_kthread+0x10/0x10
[ 1236.981238]  ret_from_fork_asm+0x1a/0x30
[ 1236.984086]  </TASK>
[ 1236.986181] Modules linked in:
[ 1236.989048] CR2: ffffc90006dc8080
[ 1236.990412] ---[ end trace 0000000000000000 ]---
[ 1236.994119] RIP: 0010:rxe_req_notify_cq+0x13a/0x350
[ 1236.998482] Code: 20 87 fd 4c 89 fe 48 ba 00 00 00 00 00 fc ff df 4c 8b 3e 49 83 ef 80 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 9b 01 00 00 <45> 8b 2f 41 80 3c 16 00 74 18 49 89 f6 48 89 f7 e8 71 20 87 fd 4c
[ 1237.006635] RSP: 0018:ffff88810222f920 EFLAGS: 00010046
[ 1237.008513] RAX: 0000000000000000 RBX: ffff88810222f920 RCX: ffffffff84c92863
[ 1237.014100] RDX: dffffc0000000000 RSI: ffff888120456d48 RDI: ffff888120456d48
[ 1237.021058] RBP: ffff88810222fa20 R08: 0000000000000003 R09: 0000000000000004
[ 1237.024939] R10: dffffc0000000000 R11: ffffed1020445f10 R12: ffff888120456d40
[ 1237.030203] R13: dffffc0000000000 R14: 1ffff1102408ada9 R15: ffffc90006dc8080
[ 1237.034299] FS:  0000000000000000(0000) GS:ffff88842600d000(0000) knlGS:0000000000000000
[ 1237.037311] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1237.042838] CR2: ffffc90006dc8080 CR3: 000000012b35f003 CR4: 0000000000f72ef0

Found with ksmbdzzer [2], a KSMBD fuzzer that drives libFuzzer with a
kcov-dataflow [1] coverage vector: it folds each instrumented
comparison/argument's runtime operand value together with its PC (the
default arm mixes them as pc⊕val) so that a new operand value at a known
site counts as new coverage.

[1] https://lwn.net/Articles/1077606/
[2] https://github.com/yskzalloc/kcov-dataflow

Fixes: 6073eb3e3175 ("smb: smbdirect: introduce smbdirect_connection_{create,destroy}_qp()")
Signed-off-by: Yunseong Kim <yunseong.kim@est.tech>
Acked-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions