{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90291", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.798Z", "datePublished": "2026-09-17T16:08:18.700Z", "dateUpdated": "2026-10-21T12:50:49.946Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:50:49.946Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmodule/dups: Fix use-after-free in kmod_dup_req lifetime handling\n\nThe kmod dups code uses RCU to ensure that a kmod_dup_req instance is freed\nonly after it is no longer referenced. When releasing an instance, the\nkmod_dup_request_delete() function removes the kmod_dup_req from the\ndup_kmod_reqs list, waits via synchronize_rcu() and finally frees it.\nHowever, this doesn't work correctly because parallel users referencing the\ninstance in kmod_dup_request_exists_wait() don't enter an RCU read-side\ncritical section. This can result in a use-after-free.\n\nThe kmod_dup_request_exists_wait() function may need to hold a valid\nreference to a kmod_dup_req instance across a blocking wait until the\ncorresponding modprobe command completes. This makes it unsuitable for RCU.\n\nFix the issue by changing the lifecycle management of kmod_dup_req to use\nreference counting." } ], "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 UAF is in kmod_dup_request_exists_wait(), reached from __request_module() when tracking a duplicate autoload. An unprivileged process hits that via socket(2) → __sys_socket() → __sock_create(), which calls request_module(\"net-pf-%d\") for an unloaded protocol family; the trigger is that local syscall, not a remote protocol message.\nAC:L - The attacker drives both sides: one socket() call's request_module() inserts a kmod_dup_req and kmod_dup_request_announce() queues kmod_dup_request_delete() for 60*HZ, then further socket() calls look up that entry, drop kmod_dup_mutex, and wait_for_completion_state() on first_req_done without rcu_read_lock, racing the delayed kfree.\nPR:L - __request_module() has no capable() check; it only calls security_kernel_module_request(), whose default LSM hook returns 0. __sock_create()'s request_module(\"net-pf-%d\") path has no capability gate either, so a normal unprivileged local user can trigger the duplicate-autoload race.\nUI:N - The attacker issues their own socket() syscalls to force concurrent request_module() calls for the same net-pf-%d name; no other user must mount a filesystem, open a file, or otherwise cooperate.\nS:U - The use-after-free is of a kmalloc'd kmod_dup_req in kernel/module/dups.c and corrupts host kernel heap. That is a standard in-kernel privilege-escalation impact inside one security authority, not a VM or IOMMU boundary crossing.\nC:H - After kmod_dup_request_delete() kfree()s the kmod_dup_req, a racing kmod_dup_request_exists_wait() still reads kmod_req->dup_ret and takes first_req_done.wait.lock inside wait_for_common(). Reclaiming that slab lets the attacker control those contents, a UAF read primitive.\nI:H - wait_for_common() takes first_req_done.wait.lock and can __prepare_to_swait() onto the completion wait queue in the already-freed kmod_dup_req. Heap spraying that object yields an attacker-controlled wait-queue/list write, a UAF write and control-flow hijack primitive.\nA:H - Using a freed kmod_dup_req's completion spinlock in wait_for_common(), or kfree() racing wait_for_completion_state(&kmod_req->first_req_done), oopses or panics the kernel even without a full exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/module/dups.c" ], "versions": [ { "version": "8660484ed1cf3261e89e0bad94c6395597e87599", "lessThan": "a3205bd1f218053575589b14caf8df667f344134", "status": "affected", "versionType": "git" }, { "version": "8660484ed1cf3261e89e0bad94c6395597e87599", "lessThan": "2c85e0fb528e039aa8ea1e9c2a1f64347f990541", "status": "affected", "versionType": "git" }, { "version": "8660484ed1cf3261e89e0bad94c6395597e87599", "lessThan": "b2709aad7599f6fd957939b60f4a8323c8f08072", "status": "affected", "versionType": "git" }, { "version": "8660484ed1cf3261e89e0bad94c6395597e87599", "lessThan": "cd2396fc9684d2cfd3f3c3f09c79d6d9d725b0ca", "status": "affected", "versionType": "git" }, { "version": "8660484ed1cf3261e89e0bad94c6395597e87599", "lessThan": "5eecb11b543f9f417bcf0dea239ff99c6af65dbd", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/module/dups.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "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": "6.4", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a3205bd1f218053575589b14caf8df667f344134" }, { "url": "https://git.kernel.org/stable/c/2c85e0fb528e039aa8ea1e9c2a1f64347f990541" }, { "url": "https://git.kernel.org/stable/c/b2709aad7599f6fd957939b60f4a8323c8f08072" }, { "url": "https://git.kernel.org/stable/c/cd2396fc9684d2cfd3f3c3f09c79d6d9d725b0ca" }, { "url": "https://git.kernel.org/stable/c/5eecb11b543f9f417bcf0dea239ff99c6af65dbd" } ], "title": "module/dups: Fix use-after-free in kmod_dup_req lifetime handling", "x_generator": { "engine": "bippy-1.2.0" } } } }