{"id":"CVE-2026-68152","state":"PUBLISHED","title":"amt: fix use-after-free in AMT delayed works","description":"In the Linux kernel, the following vulnerability has been resolved:\n\namt: fix use-after-free in AMT delayed works\n\nWhen an AMT device is removed, pending delayed works can still access\nthe freed amt_dev structure, which may result in kernel crashes or\nmemory corruption.\n\namt_dev_stop() cancels req_wq and discovery_wq with\ncancel_delayed_work_sync(), but these works can be scheduled again\nfrom event_wq after the cancellation. This allows delayed works to\naccess the freed amt_dev structure after the netdev has been released.\n\nThe following is a simple race scenario:\n\nCPU0                         CPU1\n\namt_dev_stop()\ncancel_delayed_work_sync()\n                             amt_event_work()\n                             mod_delayed_work(req_wq)\nfree netdev\n                             req_wq accesses freed amt_dev\n\nUse disable_delayed_work_sync() in amt_dev_stop() to prevent req_wq and\ndiscovery_wq from being queued again and wait for running work items\nto complete.\n\nThe delayed works are disabled after initialization in\namt_newlink() and enabled only when the device is successfully opened.\nThis keeps the delayed work lifecycle synchronized with the lifetime\nof the AMT device.","publishedAt":"2026-08-10T11:59:18.270Z","updatedAt":"2026-08-17T04:59:47.614Z","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":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"a46bfa01e01df0f6f6dc4b0be18db002d6d2dbd2","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"1a644db2cf59f164cdf3c75995bab5aadc097528","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"006340cf06881b6ff49767d8b6f3c4f7b892670c","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"ea20c44935d6142daecfa9b39d635033a7553e1b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/amt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","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/amt.c"]}],"references":["https://git.kernel.org/stable/c/a46bfa01e01df0f6f6dc4b0be18db002d6d2dbd2","https://git.kernel.org/stable/c/1a644db2cf59f164cdf3c75995bab5aadc097528","https://git.kernel.org/stable/c/006340cf06881b6ff49767d8b6f3c4f7b892670c","https://git.kernel.org/stable/c/ea20c44935d6142daecfa9b39d635033a7553e1b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68152.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68152","state":"PUBLISHED","datePublished":"2026-08-10T11:59:18.270Z","dateUpdated":"2026-08-17T04:59:47.614Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.371Z"},"containers":{"cna":{"title":"amt: fix use-after-free in AMT delayed works","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\namt: fix use-after-free in AMT delayed works\n\nWhen an AMT device is removed, pending delayed works can still access\nthe freed amt_dev structure, which may result in kernel crashes or\nmemory corruption.\n\namt_dev_stop() cancels req_wq and discovery_wq with\ncancel_delayed_work_sync(), but these works can be scheduled again\nfrom event_wq after the cancellation. This allows delayed works to\naccess the freed amt_dev structure after the netdev has been released.\n\nThe following is a simple race scenario:\n\nCPU0                         CPU1\n\namt_dev_stop()\ncancel_delayed_work_sync()\n                             amt_event_work()\n                             mod_delayed_work(req_wq)\nfree netdev\n                             req_wq accesses freed amt_dev\n\nUse disable_delayed_work_sync() in amt_dev_stop() to prevent req_wq and\ndiscovery_wq from being queued again and wait for running work items\nto complete.\n\nThe delayed works are disabled after initialization in\namt_newlink() and enabled only when the device is successfully opened.\nThis keeps the delayed work lifecycle synchronized with the lifetime\nof the AMT device."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"a46bfa01e01df0f6f6dc4b0be18db002d6d2dbd2","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"1a644db2cf59f164cdf3c75995bab5aadc097528","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"006340cf06881b6ff49767d8b6f3c4f7b892670c","versionType":"git"},{"version":"cbc21dc1cfe949e37b2a54c71511579f1899e8d4","status":"affected","lessThan":"ea20c44935d6142daecfa9b39d635033a7553e1b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/amt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","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/amt.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a46bfa01e01df0f6f6dc4b0be18db002d6d2dbd2"},{"url":"https://git.kernel.org/stable/c/1a644db2cf59f164cdf3c75995bab5aadc097528"},{"url":"https://git.kernel.org/stable/c/006340cf06881b6ff49767d8b6f3c4f7b892670c"},{"url":"https://git.kernel.org/stable/c/ea20c44935d6142daecfa9b39d635033a7553e1b"}],"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 - Exploitation requires triggering amt_dev_stop() via local rtnetlink (RTM_DELLINK/ip link del) or ndo_stop on an AMT gateway netdev; the UAF race in teardown is not reachable by remote UDP alone without this privileged local device-removal path.\nAC:L - The attacker controls both sides of the race by concurrently deleting/bringing down the AMT interface while flooding AMT UDP packets or letting discovery/request timers fire, reliably re-queuing req_wq/discovery_wq via amt_event_work during the cancel_work_sync window.\nPR:L - Creating, opening, and removing AMT virtual interfaces requires CAP_NET_ADMIN via rtnetlink, which unprivileged users can obtain inside a user network namespace (unshare -Urn), but not without any privileges at all.\nUI:N - No victim user interaction is required; a single attacker with namespace CAP_NET_ADMIN can create an AMT gateway, bring it up, and race interface teardown against self-generated AMT traffic or delayed-work events.\nS:U - Successful exploitation corrupts kernel heap memory and can escalate privileges within the same kernel, but does not inherently cross VM, container, or IOMMU security boundaries into a separate authority domain.\nC:H - Use-after-free of the amt_dev structure embedded in netdev private data allows accessing attacker-influenced freed heap memory, enabling arbitrary kernel memory disclosure through standard UAF exploitation techniques.\nI:H - The UAF on amt_dev delayed-work handlers can corrupt kernel heap metadata and adjacent objects, providing primitives for arbitrary kernel memory writes and potential code execution as acknowledged in the fix commit.\nA:H - Use-after-free in amt_req_work/amt_discovery_work accessing freed amt_dev during netdev teardown can cause kernel oops, panic, or hang, and the fix commit explicitly warns of kernel crashes and memory corruption."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:59:47.614Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}