{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80928", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.802Z", "datePublished": "2026-09-11T19:42:04.044Z", "dateUpdated": "2026-10-19T08:45:12.134Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:45:12.134Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmack: fix cred UAF in smack_file_send_sigiotask()\n\nWhen inspecting the credentials of another task, objective credentials\n(->real_cred, accessed with __task_cred()) must always be used.\n\nAccessing ->cred on a non-current task is forbidden unless that task is\nbeing created or destroyed; a task is allowed to change its own ->cred\npointer with no synchronization, and changing ->cred should only affect the\ncurrent syscall.\n\nsmack_file_send_sigiotask() was accessing both sets of credentials: First\ntsk->cred, then __task_cred(tsk).\n\nFix it, always access the objective credentials here.\n\nI have tested that this bug can lead to a KASAN-reported UAF of struct cred\nin smack_file_send_sigiotask(), and that this fix prevents the race." } ], "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 - Reachable only via local syscalls: fcntl(F_SETOWN)/O_ASYNC on a pipe or socket, then write or MSG_OOB so kill_fasync()/send_sigurg() call smack_file_send_sigiotask(). Same SIGIO path as CVE-2026-72183 (AV:L); a remote peer can raise SIGIO only on a socket the local attacker already owns.\nAC:L - The attacker controls both sides of the race: one thread loops faccessat() so access_override_creds() installs a non_rcu subjective cred that revert_creds()+put_cred() frees without RCU, while another thread writes the pipe or sends OOB to fire SIGIO. The fix author reproduced a KASAN cred UAF; the window is retryable.\nPR:L - pipe(), fcntl(F_SETOWN/F_SETFL), write(), and faccessat() need no capabilities. An unprivileged user namespace (unshare(CLONE_NEWUSER)) makes access() install the non_rcu override (non-root uid with caps, or real uid != fsuid). The UAF is kernel cred memory on the attacker’s own task.\nUI:N - No victim action is required. The attacker arms fowner on their own file, overrides their own subjective creds via faccessat(), and triggers SIGIO themselves.\nS:U - This is in-kernel cred use-after-free leading to local privilege escalation within the kernel security authority. It is not a VM escape, IOMMU bypass, or userspace sandbox boundary crossing.\nC:H - This is a use-after-free of struct cred. After free, the cred slab can be sprayed so cred->security and the derived smack_known are attacker-controlled, enabling arbitrary kernel reads through smk_access() and smack_log(). Kernel UAF scores C:H.\nI:H - The same sprayed cred/task_smack/smack_known objects yield a fake-object primitive on the SIGIO path, exploitable for control-flow hijacking and arbitrary write as with other kernel cred UAFs. Kernel UAF scores I:H.\nA:H - The fix author confirmed a KASAN use-after-free of struct cred in smack_file_send_sigiotask(). Dereferencing the freed cred on the SIGIO path, including from kill_fasync() in interrupt context, causes a kernel oops or panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/smack/smack_lsm.c" ], "versions": [ { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "a512366d84e134a9eefc2cc40eeb6e80e2ec162c", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "7c7fe043f3099d0d35002b248967f75e55345b93", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "f9c7b1f2b9d8f4176d2632743f51400855978ace", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "b5bcf3adfa27279da4401ab8f1e1a706601a92be", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "ed64aa505875a3b4defd504ee8e59e1949246a62", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "b791401bf389a1546a830d2b381ca60fe94c7870", "status": "affected", "versionType": "git" }, { "version": "3b11a1decef07c19443d24ae926982bc8ec9f4c0", "lessThan": "fedc88e38ce979a720cd2de042578cb5df3dc8de", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "security/smack/smack_lsm.c" ], "versions": [ { "version": "2.6.29", "status": "affected" }, { "version": "0", "lessThan": "2.6.29", "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": "2.6.29", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a512366d84e134a9eefc2cc40eeb6e80e2ec162c" }, { "url": "https://git.kernel.org/stable/c/7c7fe043f3099d0d35002b248967f75e55345b93" }, { "url": "https://git.kernel.org/stable/c/f9c7b1f2b9d8f4176d2632743f51400855978ace" }, { "url": "https://git.kernel.org/stable/c/b5bcf3adfa27279da4401ab8f1e1a706601a92be" }, { "url": "https://git.kernel.org/stable/c/ed64aa505875a3b4defd504ee8e59e1949246a62" }, { "url": "https://git.kernel.org/stable/c/b791401bf389a1546a830d2b381ca60fe94c7870" }, { "url": "https://git.kernel.org/stable/c/fedc88e38ce979a720cd2de042578cb5df3dc8de" } ], "title": "smack: fix cred UAF in smack_file_send_sigiotask()", "x_generator": { "engine": "bippy-1.2.0" } } } }