{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49700", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T02:21:30.443Z", "datePublished": "2025-02-26T02:24:20.878Z", "dateUpdated": "2026-08-05T08:56:04.704Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:56:04.704Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: add missing TID updates on slab deactivation\n\nThe fastpath in slab_alloc_node() assumes that c->slab is stable as long as\nthe TID stays the same. However, two places in __slab_alloc() currently\ndon't update the TID when deactivating the CPU slab.\n\nIf multiple operations race the right way, this could lead to an object\ngetting lost; or, in an even more unlikely situation, it could even lead to\nan object being freed onto the wrong slab's freelist, messing up the\n`inuse` counter and eventually causing a page to be freed to the page\nallocator while it still contains slab objects.\n\n(I haven't actually tested these cases though, this is just based on\nlooking at the code. Writing testcases for this stuff seems like it'd be\na pain...)\n\nThe race leading to state inconsistency is (all operations on the same CPU\nand kmem_cache):\n\n - task A: begin do_slab_free():\n - read TID\n - read pcpu freelist (==NULL)\n - check `slab == c->slab` (true)\n - [PREEMPT A->B]\n - task B: begin slab_alloc_node():\n - fastpath fails (`c->freelist` is NULL)\n - enter __slab_alloc()\n - slub_get_cpu_ptr() (disables preemption)\n - enter ___slab_alloc()\n - take local_lock_irqsave()\n - read c->freelist as NULL\n - get_freelist() returns NULL\n - write `c->slab = NULL`\n - drop local_unlock_irqrestore()\n - goto new_slab\n - slub_percpu_partial() is NULL\n - get_partial() returns NULL\n - slub_put_cpu_ptr() (enables preemption)\n - [PREEMPT B->A]\n - task A: finish do_slab_free():\n - this_cpu_cmpxchg_double() succeeds()\n - [CORRUPT STATE: c->slab==NULL, c->freelist!=NULL]\n\nFrom there, the object on c->freelist will get lost if task B is allowed to\ncontinue from here: It will proceed to the retry_load_slab label,\nset c->slab, then jump to load_freelist, which clobbers c->freelist.\n\nBut if we instead continue as follows, we get worse corruption:\n\n - task A: run __slab_free() on object from other struct slab:\n - CPU_PARTIAL_FREE case (slab was on no list, is now on pcpu partial)\n - task A: run slab_alloc_node() with NUMA node constraint:\n - fastpath fails (c->slab is NULL)\n - call __slab_alloc()\n - slub_get_cpu_ptr() (disables preemption)\n - enter ___slab_alloc()\n - c->slab is NULL: goto new_slab\n - slub_percpu_partial() is non-NULL\n - set c->slab to slub_percpu_partial(c)\n - [CORRUPT STATE: c->slab points to slab-1, c->freelist has objects\n from slab-2]\n - goto redo\n - node_match() fails\n - goto deactivate_slab\n - existing c->freelist is passed into deactivate_slab()\n - inuse count of slab-1 is decremented to account for object from\n slab-2\n\nAt this point, the inuse count of slab-1 is 1 lower than it should be.\nThis means that if we free all allocated objects in slab-1 except for one,\nSLUB will think that slab-1 is completely unused, and may free its page,\nleading to use-after-free." } ], "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 in the core SLUB allocator (mm/slub.c ___slab_alloc/do_slab_free) and is reached by local concurrent kernel object alloc/free via ordinary syscalls, not by parsing remote network protocol input.\nAC:L - An unprivileged attacker controls both sides of the race by pinning threads to one CPU and hammering alloc/free on the same kmem_cache; the missing TID bump also leaves an IRQ-enabled window, so success is not dependent on conditions outside attacker influence.\nPR:L - Any unprivileged local user can drive SLUB alloc/free through normal syscalls (sockets, pipes, messages, etc.), and the NUMA-constrained path used for the worst UAF escalation is reachable via set_mempolicy without real root.\nUI:N - The attacker initiates and completes the racing alloc/free sequence on their own threads; no victim action such as mounting a filesystem or opening a crafted file is required.\nS:U - Impact is kernel memory corruption and potential local privilege escalation within the same OS security authority; this is not a VM escape, IOMMU bypass, or other cross-boundary breakout.\nC:H - The documented end state frees a slab page that still contains live objects, yielding a use-after-free that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same use-after-free of slab objects enables heap spraying and arbitrary write/control-flow hijack primitives against reclaimed kernel memory.\nA:H - Use-after-free and freelist/inuse corruption in SLUB reliably cause kernel oops, panic, or hang even when not fully exploited for code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/slub.c" ], "versions": [ { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "308c6d0e1f200fd26c71270c6e6bfcf0fc6ff082", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "d6a597450e686d4c6388bd3cdcb17224b4dae7f0", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "e2b2f0e2e34d71ae6c2a1114fd3c525930e84bc7", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "e7e3e90d671078455a3a08189f89d85b3da2de9e", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "6c32496964da0dc230cea763a0e934b2e02dabd5", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "0515cc9b6b24877f59b222ade704bfaa42caa2a6", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "197e257da473c725dfe47759c3ee02f2398d8ea5", "status": "affected", "versionType": "git" }, { "version": "03e404af26dc2ea0d278d7a342de0aab394793ce", "lessThan": "eeaa345e128515135ccb864c04482180c08e3259", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/slub.c" ], "versions": [ { "version": "3.1", "status": "affected" }, { "version": "0", "lessThan": "3.1", "status": "unaffected", "versionType": "semver" }, { "version": "4.9.323", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.288", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.252", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.205", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.130", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.54", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18.8", "lessThanOrEqual": "5.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.19", "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": "3.1", "versionEndExcluding": "4.9.323" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "4.14.288" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "4.19.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.4.205" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.10.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.15.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.18.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/308c6d0e1f200fd26c71270c6e6bfcf0fc6ff082" }, { "url": "https://git.kernel.org/stable/c/d6a597450e686d4c6388bd3cdcb17224b4dae7f0" }, { "url": "https://git.kernel.org/stable/c/e2b2f0e2e34d71ae6c2a1114fd3c525930e84bc7" }, { "url": "https://git.kernel.org/stable/c/e7e3e90d671078455a3a08189f89d85b3da2de9e" }, { "url": "https://git.kernel.org/stable/c/6c32496964da0dc230cea763a0e934b2e02dabd5" }, { "url": "https://git.kernel.org/stable/c/0515cc9b6b24877f59b222ade704bfaa42caa2a6" }, { "url": "https://git.kernel.org/stable/c/197e257da473c725dfe47759c3ee02f2398d8ea5" }, { "url": "https://git.kernel.org/stable/c/eeaa345e128515135ccb864c04482180c08e3259" } ], "title": "mm/slub: add missing TID updates on slab deactivation", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2022-49700", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T18:14:57.244122Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T18:22:30.769Z" } } ] } }