In the Linux kernel, the following vulnerability has been resolved:

smb: smbdirect: free completion queues with ibfreecq()

smbdirectconnectiondestroyqp() creates the send and receive completion queues with iballoccqany(), which for IBPOLLWORKQUEUE arms an internal completion handler that runs ibcqpollwork() on a workqueue. Tearing those CQs down with ibdestroycq() 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 rxereceiver() after rdmadestroyqp() -- the handler re-queues ibcqpollwork() on the already-freed CQ, and a follow-on access faults in rxereqnotifycq().

Use ibfreecq(), which cancelworksync()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 ibcqpollwork+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 ibcqpollwork [ 1236.609525] Call Trace: [ 1236.609536] <TASK> [ 1236.609545] dumpstack+0x21/0x60 [ 1236.609562] dumpstacklvl+0xc2/0x100 [ 1236.609573] printaddressdescription+0x77/0x200 [ 1236.609587] ? ibcqpollwork+0xd0/0x1a0 [ 1236.609597] printreport+0x58/0x70 [ 1236.609607] kasanreport+0x117/0x150 [ 1236.609623] ? ibcqpollwork+0xd0/0x1a0 [ 1236.609636] ? processscheduledworks+0x954/0x1600 [ 1236.609650] ibcqpollwork+0xd0/0x1a0 [ 1236.609662] ? processscheduledworks+0x954/0x1600 [ 1236.609674] processscheduledworks+0xc22/0x1600 [ 1236.609698] ? pfxprocessscheduledworks+0x10/0x10 [ 1236.609713] ? pfxassignwork+0x10/0x10 [ 1236.609726] ? lockisheldtype+0x7b/0x110 [ 1236.609741] workerthread+0x975/0xee0 [ 1236.609757] ? pfxdorawspinlock+0x10/0x10 [ 1236.609775] ? kthreadparkme+0x21e/0x260 [ 1236.609789] kthread+0x3a6/0x490 [ 1236.609800] ? pfxworkerthread+0x10/0x10 [ 1236.609809] ? pfxkthread+0x10/0x10 [ 1236.609820] retfromfork+0x55a/0xa20 [ 1236.609835] ? pfxretfromfork+0x10/0x10 [ 1236.609850] ? pfxkthread+0x10/0x10 [ 1236.609861] retfromforkasm+0x1a/0x30 [ 1236.609880] </TASK> [ 1236.609886] [ 1236.661292] Allocated by task 5076: [ 1236.662640] kasansavetrack+0x3e/0x80 [ 1236.663842] kasankmalloc+0x72/0x90 [ 1236.664763] kmallocnoprof+0x2b0/0x5d0 [ 1236.665356] iballoccq+0x284/0x1000 [ 1236.666573] iballoccqany+0x23e/0x340 [ 1236.668654] smbdirectconnectioncreateqp+0x6f7/0x1070 [ 1236.669757] smbdirectacceptconnectrequest+0x500/0x1ca0 [ 1236.672625] smbdirectlistenrdmaeventhandler+0x1655/0x1c50 [ 1236.673930] cmalistenhandler+0x1bf/0x260 [ 1236.674923] cmacmeventhandler+0x128/0x380 [ 1236.676926] cmaibreqhandler+0x2d3d/0x4de0 [ 1236.678368] cmprocesswork+0xb0/0x530 [ 1236.680454] cmqueueworkunlock+0xb1/0x230 [ 1236.681673] cmworkhandler+0x969f/0xdca0 [ 1236.682704] processscheduledworks+0xc22/0x1600 [ 1236.683447] workerthread+0x975/0xee0 [ 1236.685901] kthread+0x3a6/0x490 [ 1236.688164] retfromfork+0x55a/0xa20 [ 1236.689522] retfromforkasm+0x1a/0x30 [ 1236.690073] [ 1236.690378] Freed by task 5137: [ 1236.692242] kasansavetrack+0x3e/0x80 [ 1236.694272] kasansavefreeinfo+0x40/0x50 [ 1236.695514] kasanslabfree+0x3a/0x60 [ 1236.696773] kfree+0x14e/0x4e0 [ 1236.697216] ibdestroycquser+0x18d/0x250 [ 1236.699817] smbdirectconnectiondestroyqp+0xf2/0x280 [ 1236.702115] smbdirectsocketdestroysync+0x1607/0x2720 [ 1236.704062] smbdirectsocketrelease+0x140/0x280 [ 1236.705286] smbdirectfreetranspor ---truncated---

apparmor: fix use-after-free in rawdata dedup loop