{"id":"CVE-2026-74606","state":"PUBLISHED","title":"eventfs: Fix use-after-free in eventfs_remove_rec()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\neventfs: Fix use-after-free in eventfs_remove_rec()\n\neventfs_remove_rec() recursively removes the child at the current loop\nposition. After the recursive call returns, list_for_each_entry() advances\nby reading list.next from the removed child.\n\nIf free_ei() drops the final reference, release_ei() reuses the list/rcu\nunion to queue an SRCU callback. The child may be freed before that read.\nThe eventfs_mutex serializes list updates, but it does not keep the removed\nchild alive or prevent the SRCU callback from running.\n\nUse list_for_each_entry_safe() to save the next sibling before recursively\nremoving the current child.","publishedAt":"2026-08-22T15:31:53.819Z","updatedAt":"2026-08-25T05:40:31.060Z","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":"5dfb04100326f70e3b2d2872c2476ed20b804837","status":"affected","lessThan":"b77581b25e213e83b79ce11eb30024e55ceeb3e9","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"f161d7861a0bfdf10af6b738b3b57636204661fb","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"5635211b44969f4816e29ec4d5f8665fb39535d0","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"74bb1eaf72d185a78c879eb2678ea500f82f46a8","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"fd73b691702170d37d66f4b0278530cea8ed419a","versionType":"git"},{"version":"5a43badefe0eccca0c26144c0a44b8d417ce8103","status":"affected","versionType":"git"},{"version":"6.6.18","status":"affected","lessThan":"6.6.152","versionType":"semver"},{"version":"6.7.6","status":"affected","lessThan":"6.8","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/tracefs/event_inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","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":["fs/tracefs/event_inode.c"]}],"references":["https://git.kernel.org/stable/c/b77581b25e213e83b79ce11eb30024e55ceeb3e9","https://git.kernel.org/stable/c/f161d7861a0bfdf10af6b738b3b57636204661fb","https://git.kernel.org/stable/c/5635211b44969f4816e29ec4d5f8665fb39535d0","https://git.kernel.org/stable/c/74bb1eaf72d185a78c879eb2678ea500f82f46a8","https://git.kernel.org/stable/c/fd73b691702170d37d66f4b0278530cea8ed419a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74606.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74606","state":"PUBLISHED","datePublished":"2026-08-22T15:31:53.819Z","dateUpdated":"2026-08-25T05:40:31.060Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.920Z"},"containers":{"cna":{"title":"eventfs: Fix use-after-free in eventfs_remove_rec()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\neventfs: Fix use-after-free in eventfs_remove_rec()\n\neventfs_remove_rec() recursively removes the child at the current loop\nposition. After the recursive call returns, list_for_each_entry() advances\nby reading list.next from the removed child.\n\nIf free_ei() drops the final reference, release_ei() reuses the list/rcu\nunion to queue an SRCU callback. The child may be freed before that read.\nThe eventfs_mutex serializes list updates, but it does not keep the removed\nchild alive or prevent the SRCU callback from running.\n\nUse list_for_each_entry_safe() to save the next sibling before recursively\nremoving the current child."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5dfb04100326f70e3b2d2872c2476ed20b804837","status":"affected","lessThan":"b77581b25e213e83b79ce11eb30024e55ceeb3e9","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"f161d7861a0bfdf10af6b738b3b57636204661fb","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"5635211b44969f4816e29ec4d5f8665fb39535d0","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"74bb1eaf72d185a78c879eb2678ea500f82f46a8","versionType":"git"},{"version":"43aa6f97c2d03a52c1ddb86768575fc84344bdbb","status":"affected","lessThan":"fd73b691702170d37d66f4b0278530cea8ed419a","versionType":"git"},{"version":"5a43badefe0eccca0c26144c0a44b8d417ce8103","status":"affected","versionType":"git"},{"version":"6.6.18","status":"affected","lessThan":"6.6.152","versionType":"semver"},{"version":"6.7.6","status":"affected","lessThan":"6.8","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/tracefs/event_inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","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":["fs/tracefs/event_inode.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b77581b25e213e83b79ce11eb30024e55ceeb3e9"},{"url":"https://git.kernel.org/stable/c/f161d7861a0bfdf10af6b738b3b57636204661fb"},{"url":"https://git.kernel.org/stable/c/5635211b44969f4816e29ec4d5f8665fb39535d0"},{"url":"https://git.kernel.org/stable/c/74bb1eaf72d185a78c879eb2678ea500f82f46a8"},{"url":"https://git.kernel.org/stable/c/fd73b691702170d37d66f4b0278530cea8ed419a"}],"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 - eventfs_remove_rec() is only reached via eventfs_remove_dir()/eventfs_remove_events_dir() during tracefs event teardown (instance rmdir, dynamic event removal, module unload); tracefs is a local pseudo-fs under /sys/kernel/tracing with no network, adjacent, or physical entry path.\nAC:L - The UAF is deterministic whenever a parent eventfs_inode has 2+ children: after recursively freeing the first child, list_for_each_entry() reads list.next from repurposed freed memory; an attacker can create multiple trace events then trigger parent teardown without uncontrollable races.\nPR:L - Exploitation needs local tracefs write (kprobe_events/dynamic_events to create events, rmdir on tracing instances); paths check LOCKDOWN_TRACEFS and DAC without capable(), and tracing-group gid mounts on Android/ChromeOS/dev systems commonly grant this to unprivileged users.\nUI:N - The attacker performs all tracefs operations to create multiple eventfs children and invoke teardown in their own session; no separate victim mount, click, or configuration action is required beyond tracefs already being accessible.\nS:U - The UAF corrupts kernel heap within the tracing/eventfs subsystem on the same host; it enables local privilege escalation but does not cross VM, IOMMU, container, or other security boundaries to a different authority.\nC:H - After free_ei(), release_ei() reuses the child's list/rcu union for SRCU teardown; list_for_each_entry() then reads list.next from freed/repurposed eventfs_inode memory, a standard kernel UAF read and information-disclosure primitive.\nI:H - Freed eventfs_inode slabs can be attacker-influenced via repeated trace-event create/delete; the corrupt sibling traversal enables heap grooming for arbitrary kernel writes and local privilege escalation, not merely a bounded crash.\nA:H - Reading list.next from a freed/repurposed eventfs_inode during recursive removal reliably causes invalid pointer dereferences, kernel oops, or panic; the fault is retriggerable by repeating trace-event setup and teardown cycles."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-25T05:40:31.060Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.18","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7.6"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}