{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90173", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.791Z", "datePublished": "2026-09-17T16:07:00.463Z", "dateUpdated": "2026-10-19T08:59:10.504Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:59:10.504Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: free completion queues with ib_free_cq()\n\nsmbdirect_connection_destroy_qp() creates the send and receive completion\nqueues with ib_alloc_cq_any(), which for IB_POLL_WORKQUEUE arms an\ninternal completion handler that runs ib_cq_poll_work() on a workqueue.\nTearing those CQs down with ib_destroy_cq() frees them without first\ncancelling that poll work.\n\nIf the provider posts a completion late -- for example Soft-RoCE (rxe)\nposting an RNR error from rxe_receiver() after rdma_destroy_qp() -- the\nhandler re-queues ib_cq_poll_work() on the already-freed CQ, and a\nfollow-on access faults in rxe_req_notify_cq().\n\nUse ib_free_cq(), which cancel_work_sync()es the poll work before freeing\nthe CQ, so no completion handler can run against a freed queue.\n\n[ 1236.599526] ==================================================================\n[ 1236.602142] BUG: KASAN: slab-use-after-free in ib_cq_poll_work+0xd0/0x1a0\n[ 1236.605524] Read of size 8 at addr ffff888111865800 by task kworker/4:1H/82\n[ 1236.609017]\n[ 1236.609270] CPU: 4 UID: 0 PID: 82 Comm: kworker/4:1H Not tainted 7.2.0-rc3-next-20260717-virtme #110 PREEMPT(lazy)\n[ 1236.609287] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 1236.609498] Workqueue: ib-comp-wq ib_cq_poll_work\n[ 1236.609525] Call Trace:\n[ 1236.609536] \n[ 1236.609545] __dump_stack+0x21/0x60\n[ 1236.609562] dump_stack_lvl+0xc2/0x100\n[ 1236.609573] print_address_description+0x77/0x200\n[ 1236.609587] ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609597] print_report+0x58/0x70\n[ 1236.609607] kasan_report+0x117/0x150\n[ 1236.609623] ? ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609636] ? process_scheduled_works+0x954/0x1600\n[ 1236.609650] ib_cq_poll_work+0xd0/0x1a0\n[ 1236.609662] ? process_scheduled_works+0x954/0x1600\n[ 1236.609674] process_scheduled_works+0xc22/0x1600\n[ 1236.609698] ? __pfx_process_scheduled_works+0x10/0x10\n[ 1236.609713] ? __pfx_assign_work+0x10/0x10\n[ 1236.609726] ? lock_is_held_type+0x7b/0x110\n[ 1236.609741] worker_thread+0x975/0xee0\n[ 1236.609757] ? __pfx_do_raw_spin_lock+0x10/0x10\n[ 1236.609775] ? __kthread_parkme+0x21e/0x260\n[ 1236.609789] kthread+0x3a6/0x490\n[ 1236.609800] ? __pfx_worker_thread+0x10/0x10\n[ 1236.609809] ? __pfx_kthread+0x10/0x10\n[ 1236.609820] ret_from_fork+0x55a/0xa20\n[ 1236.609835] ? __pfx_ret_from_fork+0x10/0x10\n[ 1236.609850] ? __pfx_kthread+0x10/0x10\n[ 1236.609861] ret_from_fork_asm+0x1a/0x30\n[ 1236.609880] \n[ 1236.609886]\n[ 1236.661292] Allocated by task 5076:\n[ 1236.662640] kasan_save_track+0x3e/0x80\n[ 1236.663842] __kasan_kmalloc+0x72/0x90\n[ 1236.664763] __kmalloc_noprof+0x2b0/0x5d0\n[ 1236.665356] __ib_alloc_cq+0x284/0x1000\n[ 1236.666573] __ib_alloc_cq_any+0x23e/0x340\n[ 1236.668654] smbdirect_connection_create_qp+0x6f7/0x1070\n[ 1236.669757] smbdirect_accept_connect_request+0x500/0x1ca0\n[ 1236.672625] smbdirect_listen_rdma_event_handler+0x1655/0x1c50\n[ 1236.673930] cma_listen_handler+0x1bf/0x260\n[ 1236.674923] cma_cm_event_handler+0x128/0x380\n[ 1236.676926] cma_ib_req_handler+0x2d3d/0x4de0\n[ 1236.678368] cm_process_work+0xb0/0x530\n[ 1236.680454] cm_queue_work_unlock+0xb1/0x230\n[ 1236.681673] cm_work_handler+0x969f/0xdca0\n[ 1236.682704] process_scheduled_works+0xc22/0x1600\n[ 1236.683447] worker_thread+0x975/0xee0\n[ 1236.685901] kthread+0x3a6/0x490\n[ 1236.688164] ret_from_fork+0x55a/0xa20\n[ 1236.689522] ret_from_fork_asm+0x1a/0x30\n[ 1236.690073]\n[ 1236.690378] Freed by task 5137:\n[ 1236.692242] kasan_save_track+0x3e/0x80\n[ 1236.694272] kasan_save_free_info+0x40/0x50\n[ 1236.695514] __kasan_slab_free+0x3a/0x60\n[ 1236.696773] kfree+0x14e/0x4e0\n[ 1236.697216] ib_destroy_cq_user+0x18d/0x250\n[ 1236.699817] smbdirect_connection_destroy_qp+0xf2/0x280\n[ 1236.702115] smbdirect_socket_destroy_sync+0x1607/0x2720\n[ 1236.704062] smbdirect_socket_release+0x140/0x280\n[ 1236.705286] smb_direct_free_transpor\n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - A remote InfiniBand CM CONNECT_REQUEST handled by smbdirect_listen_rdma_event_handler() reaches smbdirect_accept_connect_request(), which allocates the CQs; the same peer's later RDMA packets make rxe_receiver() post a completion after rdma_destroy_qp(), use-after-freeing them. ksmbd listens for this on RoCE/IB port 445 and iWARP port 5445.\nAC:L - The attacker controls both sides: they send the CONNECT_REQUEST that creates the CQs in smbdirect_connection_create_qp(), then disconnect or keep sending RDMA packets so rxe_receiver() queues ib_cq_poll_work() while smbdirect_connection_destroy_qp() frees the CQ with ib_destroy_cq() instead of ib_free_cq(), skipping cancel_work_sync().\nPR:N - CQ allocation runs in smbdirect_accept_connect_request() on the unauthenticated RDMA CM CONNECT_REQUEST path, before SMB Direct negotiate completes and before any SMB2 SESSION_SETUP. Connection teardown through __ksmbd_conn_release_work() likewise needs no credentials.\nUI:N - The attacker alone sends the RDMA CM CONNECT_REQUEST to the ksmbd listener started by smb_direct_listen() and later drops that connection so ksmbd_conn_handler_loop() calls smbdirect_connection_destroy_qp(); no local user mount, click, or prompt is required.\nS:U - The use-after-free is of the kernel struct ib_cq allocated by __ib_alloc_cq() and later touched by ib_cq_poll_work() on the same host; it does not cross a VM, IOMMU, or sandbox boundary.\nC:H - ib_cq_poll_work() reads a kmalloc-freed struct ib_cq (cq->wc and cq->device) after ib_destroy_cq_user(); reclaiming that slab object lets the attacker supply a fake ib_device and obtain a kernel read primitive through the poll/notify path.\nI:H - The same reclaimed ib_cq is used as cq->device->ops.poll_cq and req_notify_cq from ib_cq_poll_work(), so a sprayed fake ops table yields a kernel function-pointer hijack, not merely a crash.\nA:H - The demonstrated KASAN use-after-free in ib_cq_poll_work() and the follow-on oops in rxe_req_notify_cq() crash the kernel; a remote peer can repeat connect-and-teardown against the ksmbd SMB Direct listener." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/smbdirect/connection.c" ], "versions": [ { "version": "6073eb3e31756d569c4853fb22724525739d0e0c", "lessThan": "8a953b1a47fffb71e70767bc1e914401e3c2f27f", "status": "affected", "versionType": "git" }, { "version": "6073eb3e31756d569c4853fb22724525739d0e0c", "lessThan": "fe2c0cacbcff9d56c03b296f68f22151c4223b04", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/smbdirect/connection.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8a953b1a47fffb71e70767bc1e914401e3c2f27f" }, { "url": "https://git.kernel.org/stable/c/fe2c0cacbcff9d56c03b296f68f22151c4223b04" } ], "title": "smb: smbdirect: free completion queues with ib_free_cq()", "x_generator": { "engine": "bippy-1.2.0" } } } }