{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89508", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.716Z", "datePublished": "2026-09-11T19:43:54.682Z", "dateUpdated": "2026-10-19T08:47:59.672Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:59.672Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ucma: Lock the handler in ucma_set_ib_path()\n\nucma_set_ib_path() calls ucma_event_handler() straight from the write()\npath, without the handler lock that keeps ctx->file stable while a uevent\nis queued. The handler re-reads ctx->file for every dereference:\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\nA concurrent ucma_migrate_id() reassigns ctx->file while the SET_OPTION\ncaller sleeps in mutex_lock(), so the list_add_tail() lands on file B's\nevent_list while only file A's mutex is held, racing every other user of\nthat list:\n\n BUG: KASAN: slab-use-after-free in __list_add_valid_or_report+0x1aa/0x1c0\n Read of size 8 at addr ffff888153c6a418 by task poc_corr/486\n Call Trace:\n __list_add_valid_or_report+0x1aa/0x1c0\n ucma_event_handler+0x1be/0xc00\n ucma_set_ib_path+0x45e/0x710\n ucma_set_option+0x32e/0x590\n ucma_write+0x1f9/0x330\n Allocated by task 505:\n ucma_write_cm_event+0x1a1/0x660\n Freed by task 505:\n kfree+0x1da/0x4c0\n ucma_get_event+0x5d5/0x7e0\n\nThe freed object is a ucma_event that another thread dequeued from file B's\nlist under file B's mutex. File A's mut is left held on top of that,\nwedging its next writer in uninterruptible sleep.\n\nThis path needs a bound and address-resolved cm_id, so it requires an RDMA\ndevice to be present.\n\nTake the handler lock around the call." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via write() on /dev/infiniband/rdma_cm (SET_OPTION -> ucma_set_option -> ucma_set_ib_path). A remote RDMA peer cannot invoke this path; in-kernel CM event delivery already holds the handler lock that this write path omitted.\nAC:L - The attacker controls both sides of the race: one thread issues SET_OPTION (RDMA_OPTION_IB_PATH) while another MIGRATE_IDs the cm_id to a second fd and a third GET_EVENTs to free the uevent. The window is the mutex_lock() sleep in ucma_event_handler, which the attacker can widen, and it was reproduced by poc_corr.\nPR:L - ucma is a miscdevice with mode 0666 and ucma_write() has no capability check. Any unprivileged local user can open /dev/infiniband/rdma_cm, CREATE_ID, resolve an address on an existing RDMA device, then issue SET_OPTION and MIGRATE_ID.\nUI:N - The attacker opens rdma_cm, creates and migrates their own cm_id, and issues the concurrent SET_OPTION and GET_EVENT writes themselves; no other user or administrator action is required.\nS:U - The use-after-free and list corruption are confined to host-kernel objects (ucma_event and file event_list). This is a standard local kernel compromise and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - The race is a slab use-after-free of struct ucma_event (KASAN in __list_add_valid_or_report after GET_EVENT kfree). Reclaiming the freed object gives the attacker control over list pointers and event contents, enabling disclosure of kernel memory.\nI:H - list_add_tail runs on file B's event_list while only file A's mutex is held, corrupting list pointers. Combined with UAF reclaim of ucma_event, this is a classic kernel list-unlink arbitrary-write primitive suitable for control-flow hijacking.\nA:H - The UAF and list_debug BUG can oops the kernel, and the mismatched mutex_unlock leaves file A's mut held so the next writer sleeps uninterruptibly in D state, hanging the system." } ] } ], "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": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "3dd07b369371a2f29e1c3caf1ade85bb92b4c551", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "b2da0d488a1c72956ebb0a57015ee8ee6a2f7748", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "a7f8d26e653ee43b0b572984b8ec544d3b3b6f3c", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "71dc206f2e2a645dac78879768762451aa1799f7", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "764586f8f6180084c5a7d622120f526acc6ce0c9", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "28ac2dd416482d1c763c4af5d61af465b387fb50", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "43a7d8ae9f645dc00235cfa4bf57673c20b769f8", "status": "affected", "versionType": "git" }, { "version": "09e328e47a695b0d346598f5d6593ee598e64885", "lessThan": "ecbe7d36dc2de07e5dfbb4a8ff5b315ab43de820", "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": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "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", "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": "5.10", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3dd07b369371a2f29e1c3caf1ade85bb92b4c551" }, { "url": "https://git.kernel.org/stable/c/b2da0d488a1c72956ebb0a57015ee8ee6a2f7748" }, { "url": "https://git.kernel.org/stable/c/a7f8d26e653ee43b0b572984b8ec544d3b3b6f3c" }, { "url": "https://git.kernel.org/stable/c/71dc206f2e2a645dac78879768762451aa1799f7" }, { "url": "https://git.kernel.org/stable/c/764586f8f6180084c5a7d622120f526acc6ce0c9" }, { "url": "https://git.kernel.org/stable/c/28ac2dd416482d1c763c4af5d61af465b387fb50" }, { "url": "https://git.kernel.org/stable/c/43a7d8ae9f645dc00235cfa4bf57673c20b769f8" }, { "url": "https://git.kernel.org/stable/c/ecbe7d36dc2de07e5dfbb4a8ff5b315ab43de820" } ], "title": "RDMA/ucma: Lock the handler in ucma_set_ib_path()", "x_generator": { "engine": "bippy-1.2.0" } } } }