{"id":"CVE-2026-74725","state":"PUBLISHED","title":"enic: fix tx_hang_reset use-after-free on device removal","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nenic: fix tx_hang_reset use-after-free on device removal\n\nenic_remove() cancels the reset and change_mtu_work items but does not\ncancel tx_hang_reset. A TX timeout that fires while the device is being\nremoved can schedule enic_tx_hang_reset() so that it runs after\nfree_netdev(), resulting in a use-after-free.\n\ncancel_work_sync() alone is not sufficient here: the still-live watchdog\nand notify paths can re-schedule these work items in the window between\nthe cancel and unregister_netdev(). Use disable_work_sync(), which\ncancels the work and blocks any subsequent schedule_work() from\nrequeuing it, and apply it to the reset and change_mtu_work items as\nwell so the same requeue race is closed for all teardown work.","publishedAt":"2026-08-22T15:33:16.460Z","updatedAt":"2026-10-16T19:16:12.099Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"8619865f34fb3b130b567855382a5c4aadd522b9","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"e506e704b74748ffd0e1c92a7453ca2a959f832b","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"4f3464fc6c1f26afc504fd525c574f2bc14c9d42","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"ec680ea4ba1bca92a767fb7e7869758bfdd886e3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/cisco/enic/enic_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.4","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/cisco/enic/enic_main.c"]}],"references":["https://git.kernel.org/stable/c/8619865f34fb3b130b567855382a5c4aadd522b9","https://git.kernel.org/stable/c/e506e704b74748ffd0e1c92a7453ca2a959f832b","https://git.kernel.org/stable/c/4f3464fc6c1f26afc504fd525c574f2bc14c9d42","https://git.kernel.org/stable/c/ec680ea4ba1bca92a767fb7e7869758bfdd886e3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74725.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74725","state":"PUBLISHED","datePublished":"2026-08-22T15:33:16.460Z","dateUpdated":"2026-10-16T19:16:12.099Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.929Z"},"containers":{"cna":{"title":"enic: fix tx_hang_reset use-after-free on device removal","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nenic: fix tx_hang_reset use-after-free on device removal\n\nenic_remove() cancels the reset and change_mtu_work items but does not\ncancel tx_hang_reset. A TX timeout that fires while the device is being\nremoved can schedule enic_tx_hang_reset() so that it runs after\nfree_netdev(), resulting in a use-after-free.\n\ncancel_work_sync() alone is not sufficient here: the still-live watchdog\nand notify paths can re-schedule these work items in the window between\nthe cancel and unregister_netdev(). Use disable_work_sync(), which\ncancels the work and blocks any subsequent schedule_work() from\nrequeuing it, and apply it to the reset and change_mtu_work items as\nwell so the same requeue race is closed for all teardown work."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"8619865f34fb3b130b567855382a5c4aadd522b9","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"e506e704b74748ffd0e1c92a7453ca2a959f832b","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"4f3464fc6c1f26afc504fd525c574f2bc14c9d42","versionType":"git"},{"version":"937317c7c1097aa878a5000e3aab616eb5c590c0","status":"affected","lessThan":"ec680ea4ba1bca92a767fb7e7869758bfdd886e3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/cisco/enic/enic_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.4","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/cisco/enic/enic_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8619865f34fb3b130b567855382a5c4aadd522b9"},{"url":"https://git.kernel.org/stable/c/e506e704b74748ffd0e1c92a7453ca2a959f832b"},{"url":"https://git.kernel.org/stable/c/4f3464fc6c1f26afc504fd525c574f2bc14c9d42"},{"url":"https://git.kernel.org/stable/c/ec680ea4ba1bca92a767fb7e7869758bfdd886e3"}],"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 occurs during enic_remove() PCI/driver teardown (sysfs unbind, rmmod, or hot-unplug); TX timeout is raised by the local netdev watchdog, not by remote packet processing, and there is no standalone network path into enic_remove itself.\nAC:L - This is a workqueue race during removal: once teardown starts the netdev can still be up so the watchdog schedules enic_tx_hang_reset, and an attacker can reliably drive TX timeout by stalling or flooding xmit on the still-registered interface while removal proceeds.\nPR:L - PCI unbind/module unload needs elevated privileges, but an unprivileged local or tenant workload can supply the concurrent netdev watchdog TX timeout (local/remote traffic on the Cisco VIC uplink) that schedules tx_hang_reset; per driver-removal UAF precedent, PR:L.\nUI:N - No victim interaction is required beyond routine driver removal, module unload, or hypervisor VNIC hot-unplug; monitoring and network traffic on the live interface can schedule tx_hang_reset during teardown without cooperation.\nS:U - Impact is use-after-free of netdev_priv enic memory in the host/guest kernel, enabling crash or privilege escalation within the same kernel security authority; it does not cross VM, hypervisor, IOMMU, or container boundaries.\nC:H - enic_tx_hang_reset dereferences freed enic/netdev memory via container_of(work, struct enic, tx_hang_reset); UAF on the unified netdev slab enables arbitrary kernel memory disclosure once the object is reallocated.\nI:H - The scheduled work performs hang reset, stop/open, and notifier calls through the dangling enic pointer, giving attacker-influenced writes and control-flow hijack primitives typical of netdev driver UAF exploitation.\nA:H - Use-after-free during enic_tx_hang_reset reliably causes kernel oops/panic when the work runs after free_netdev(), and even attempted exploitation crashes the system on dangling enic/netdev accesses."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-25T05:42:05.934Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74725","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:15:41.206988Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:16:12.099Z"}}]}}}