{"id":"CVE-2026-90172","summary":"smb: smbdirect: destroy QP before mem pools on accept failure","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: destroy QP before mem pools on accept failure\n\nOn the rdma_accept_failed error path of\nsmbdirect_accept_connect_request(), the receive io posted just above is\nowned by the QP (recv_io is set to NULL after a successful post).  The\nerror path fell through to smbdirect_connection_destroy_mem_pools()\nbefore smbdirect_connection_destroy_qp(), so the mem pools and the\nrecv_io slab cache were destroyed while that recv_io was still\noutstanding on the QP.\n\nThe drain in smbdirect_connection_destroy_qp() (ib_drain_qp()) is what\nruns the recv completion that returns the recv_io to the free list, so\ndestroying the pools first leaves the object outstanding at\nkmem_cache_destroy() time (\"Slab cache still has objects\") and later\nfrees it into an already-destroyed mempool (mempool_free_bulk\nNULL-pointer dereference).\n\nGive rdma_accept_failed its own teardown that drains the QP first, then\ndestroys the mem pools, and returns.  The remaining labels\n(post_recv_io_failed onward) run before the recv_io was ever posted, so\nthey keep the mem-pools-then-qp order.\n\nThe outstanding recv_io at kmem_cache_destroy() time:\n\n[ 3487.344647] =============================================================================\n[ 3487.349942] BUG smbdirect_recv_io_cache_ffff88811ba99000 (Not tainted): Objects remaining on __kmem_cache_shutdown()\n[ 3487.356078] -----------------------------------------------------------------------------\n[ 3487.356078]\n[ 3487.356738] Object 0xffff8881511c3440 @offset=13376\n[ 3487.358464] Allocated in mempool_alloc_noprof+0x18c/0x290 age=1194 cpu=6 pid=22254\n[ 3487.361197]  mempool_alloc_noprof+0x18c/0x290\n[ 3487.361542]  smbdirect_connection_create_mem_pools+0x405/0x780\n[ 3487.361972]  smbdirect_accept_connect_request+0x5a8/0x1b80\n[ 3487.362359]  smbdirect_listen_rdma_event_handler+0x1579/0x1b90\n[ 3487.362779]  cma_cm_event_handler+0x9c/0x230\n[ 3487.363096]  cma_ib_req_handler+0x2682/0x45d0\n[ 3487.363414]  cm_process_work+0x56/0x3d0\n[ 3487.363676]  cm_work_handler+0x8a0e/0xd000\n[ 3487.367496]  process_scheduled_works+0xa07/0x13a0\n[ 3487.367859]  worker_thread+0x7c9/0xc80\n[ 3487.368148]  kthread+0x341/0x430\n[ 3487.368407]  ret_from_fork+0x3a8/0x7a0\n[ 3487.368704]  ret_from_fork_asm+0x1a/0x30\n[ 3487.370307] Slab 0xffffea0005447000 objects=19 used=1 fp=0xffff8881511c0040 flags=0x100000000000240(workingset|head|node=0|zone=2)\n[ 3487.372840] ------------[ cut here ]------------\n[ 3487.373195] WARNING: mm/slub.c:1244 at __slab_err+0x1a/0x30, CPU#6: kworker/6:84/22254\n[ 3487.373759] Modules linked in:\n[ 3487.373993] CPU: 6 UID: 0 PID: 22254 Comm: kworker/6:84 Tainted: G    B               7.1.0-next-20260623+ #88 PREEMPT(lazy)\n[ 3487.374778] Tainted: [B]=BAD_PAGE\n[ 3487.377830] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 3487.378515] Workqueue: ib_cm cm_work_handler\n[ 3487.378820] RIP: 0010:__slab_err+0x1a/0x30\n[ 3487.379129] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 e8 36 00 00 00 bf 05 00 00 00 be 01 00 00 00 e8 f7 75 45 00 90 \u003c0f\u003e 0b 90 c3 cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00\n[ 3487.383255] RSP: 0018:ffff888220fc7050 EFLAGS: 00010093\n[ 3487.383643] RAX: ffffffff8168e60a RBX: ffff88810955e640 RCX: ffff88821c381d80\n[ 3487.384158] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff870fa080\n[ 3487.384662] RBP: ffff888220fc7068 R08: ffffffff870fa087 R09: 1ffffffff0e1f410\n[ 3487.385192] R10: dffffc0000000000 R11: fffffbfff0e1f411 R12: ffffea0005447210\n[ 3487.385674] R13: ffffea0005447000 R14: ffff888220fc7068 R15: ffff88812a8ab300\n[ 3487.388932] FS:  0000000000000000(0000) GS:ffff888427e76000(0000) knlGS:0000000000000000\n[ 3487.389529] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 3487.389934] CR2: 00007ffcf2d84fd8 CR3: 0000000111d64006 CR4: 0000000000f72ef0\n[ 3487.390440] PKRU: 55555554\n[ 3487.390641] Call Trace:\n[ 3487.390826]  \u003cTASK\u003e\n[ 3\n---truncated---","modified":"2026-09-18T03:48:36.207288681Z","published":"2026-09-17T16:06:59.794Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90172.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/383a9480f5f40bc46454cce27ccfad532cedad9c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/959813a3752b459ed77b0b3eaf30b9f4c6204260"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90172.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90172"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"eb3ed1e9048cf7b2a38112f48e0f1b772bb7860d"},{"fixed":"959813a3752b459ed77b0b3eaf30b9f4c6204260"},{"fixed":"383a9480f5f40bc46454cce27ccfad532cedad9c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90172.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90172.json"}}],"schema_version":"1.9.0"}