{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89507", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.716Z", "datePublished": "2026-09-11T19:43:54.013Z", "dateUpdated": "2026-09-11T19:43:54.013Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-11T19:43:54.013Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ucma: Lock the handler in ucma_write_cm_event()\n\nctx->file may only be changed under the handler lock and the xa_lock, which\nis what stops uevents being queued for a ctx while ucma_migrate_id() moves\nit to another file. The CM core takes that lock before invoking\nucma_event_handler(), but the write() paths that queue uevents themselves\ndo not.\n\nucma_write_cm_event() re-reads ctx->file for each of its four dereferences,\nso ucma_migrate_id() can swap it mid-sequence:\n\n\tmutex_lock(&ctx->file->mut);\t\t\t/* file A */\n\tlist_add_tail(&uevent->list, &ctx->file->event_list);\t/* file B */\n\tmutex_unlock(&ctx->file->mut);\t\t\t/* file B */\n\twake_up_interruptible(&ctx->file->poll_wait);\t/* file B */\n\nThe window is the mutex_lock() itself: the writer sleeps in it while the\nmigration reassigns ctx->file. The list_add_tail() then runs on file B's\nevent_list holding only file A's mutex:\n\n list_add corruption. prev->next should be next (ffff888101320f30),\n but was ffff88814a08c418. (prev=ffff88814a075c18).\n kernel BUG at lib/list_debug.c:32!\n Call Trace:\n ucma_write_cm_event+0x36e/0x5e0\n\nand file A's mut is left held forever, wedging its next writer in D state.\nThe uevent is also stranded on a list ucma_cleanup_ctx_events() will not\nwalk, so it outlives its context. /dev/infiniband/rdma_cm is 0666 and no\nRDMA device is involved, so an unprivileged user reaches all of this.\n\nTake the handler lock, as ucma_cleanup_mc_events() does; ctx->cm_id is\npinned by the ucma_get_ctx() reference."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/infiniband/core/ucma.c"], "versions": [{"version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "lessThan": "4f8bb11dd2ff365e7cff1c9964ab4607292d364e", "status": "affected", "versionType": "git"}, {"version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "lessThan": "0be1955040a2eceed0ecfc387fdc92305411d273", "status": "affected", "versionType": "git"}, {"version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "lessThan": "f4cc21c6a8e9d392871477f9fd98d68e5ad80272", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/infiniband/core/ucma.c"], "versions": [{"version": "6.18", "status": "affected"}, {"version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "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": "6.18", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.3-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/4f8bb11dd2ff365e7cff1c9964ab4607292d364e"}, {"url": "https://git.kernel.org/stable/c/0be1955040a2eceed0ecfc387fdc92305411d273"}, {"url": "https://git.kernel.org/stable/c/f4cc21c6a8e9d392871477f9fd98d68e5ad80272"}], "title": "RDMA/ucma: Lock the handler in ucma_write_cm_event()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/infiniband/core/ucma.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "4f8bb11dd2ff365e7cff1c9964ab4607292d364e", "status": "affected", "version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "versionType": "git"}, {"lessThan": "0be1955040a2eceed0ecfc387fdc92305411d273", "status": "affected", "version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "versionType": "git"}, {"lessThan": "f4cc21c6a8e9d392871477f9fd98d68e5ad80272", "status": "affected", "version": "a3c9d0fcd3715541bbf97da2ddde9d032e2fe6d5", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/infiniband/core/ucma.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.18"}, {"lessThan": "6.18", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ucma: Lock the handler in ucma_write_cm_event()\n\nctx->file may only be changed under the handler lock and the xa_lock, which\nis what stops uevents being queued for a ctx while ucma_migrate_id() moves\nit to another file. The CM core takes that lock before invoking\nucma_event_handler(), but the write() paths that queue uevents themselves\ndo not.\n\nucma_write_cm_event() re-reads ctx->file for each of its four dereferences,\nso ucma_migrate_id() can swap it mid-sequence:\n\n\tmutex_lock(&ctx->file->mut);\t\t\t/* file A */\n\tlist_add_tail(&uevent->list, &ctx->file->event_list);\t/* file B */\n\tmutex_unlock(&ctx->file->mut);\t\t\t/* file B */\n\twake_up_interruptible(&ctx->file->poll_wait);\t/* file B */\n\nThe window is the mutex_lock() itself: the writer sleeps in it while the\nmigration reassigns ctx->file. The list_add_tail() then runs on file B's\nevent_list holding only file A's mutex:\n\n list_add corruption. prev->next should be next (ffff888101320f30),\n but was ffff88814a08c418. (prev=ffff88814a075c18).\n kernel BUG at lib/list_debug.c:32!\n Call Trace:\n ucma_write_cm_event+0x36e/0x5e0\n\nand file A's mut is left held forever, wedging its next writer in D state.\nThe uevent is also stranded on a list ucma_cleanup_ctx_events() will not\nwalk, so it outlives its context. /dev/infiniband/rdma_cm is 0666 and no\nRDMA device is involved, so an unprivileged user reaches all of this.\n\nTake the handler lock, as ucma_cleanup_mc_events() does; ctx->cm_id is\npinned by the ucma_get_ctx() reference."}], "id": "CVE-2026-89507", "lastModified": "2026-09-11T20:19:33.027", "metrics": {}, "published": "2026-09-11T20:19:33.027", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0be1955040a2eceed0ecfc387fdc92305411d273"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4f8bb11dd2ff365e7cff1c9964ab4607292d364e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f4cc21c6a8e9d392871477f9fd98d68e5ad80272"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel RDMA/ucma: Race condition leads to denial of service and kernel crash", "id": "2532319", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532319"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-367", "details": ["A flaw was found in the Linux kernel's RDMA/ucma component. A race condition exists in the `ucma_write_cm_event()` function where it re-reads a critical file pointer multiple times without proper locking. This allows another function, `ucma_migrate_id()`, to change the file pointer mid-operation. An unprivileged local user can exploit this to cause list corruption, trigger a kernel crash, and leave a mutex locked indefinitely, resulting in a denial of service."], "name": "CVE-2026-89507", "public_date": "2026-09-11T19:43:54Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89507\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89507\nhttps://git.kernel.org/stable/c/0be1955040a2eceed0ecfc387fdc92305411d273\nhttps://git.kernel.org/stable/c/4f8bb11dd2ff365e7cff1c9964ab4607292d364e\nhttps://git.kernel.org/stable/c/f4cc21c6a8e9d392871477f9fd98d68e5ad80272"], "threat_severity": "Important"}

{}