{"id":"CVE-2026-90002","state":"PUBLISHED","title":"ftrace: Take trace_array reference before accessing its ftrace_ops","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Take trace_array reference before accessing its ftrace_ops\n\nThe trace instance files set_ftrace_filter and set_ftrace_notrace was\nupdated to work with specific trace instances (trace_arrays). The issue is\nthat when these files are opened, there is a small race window where it\nwill use the ftrace_ops from the inode->private pointer to get a reference\nto the trace_array and then take its reference. The problem is that the\nftrace_ops itself could be freed. If the rmdir on the instance happens at\nthe same time the set_ftrace_filter file is opened, the rmdir could have\nalso freed the ftrace_ops and referencing it will cause a use-after-free\nbug and crash the kernel.\n\nInstead, pass in the trace_array as the file private data (NULL for the\ntop level instance), and then pass both the trace_array and the ftrace_ops\nto the ftrace_regex_open() function. If the trace_array is NULL, then it\njust uses the ftrace_ops without the need to take its reference (like\nnormal). If the ftrace_ops is NULL, that is only the case for the top\nlevel instance and the global_ops can be used.\n\nThis allows the trace_array to have its reference incremented before\ntouching the ftrace_ops that could also be freed when the instance is.","publishedAt":"2026-09-16T10:33:12.734Z","updatedAt":"2026-10-30T12:33:46.379Z","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":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"0124b36a7eac1dd0402146fc6c1f732877b9cd9f","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"ffe16fe221e25cd1915602e6753c3d3285ed9a98","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"8f062a6bfeb4b4e18d469a673aec23a7b73c3e8a","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"29266da8ee1d9be656b1f22460c49538e1930658","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"177cd8966325f0ffffa3c9381f9e0422019a3973","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"83fd7eca5ab0d3ac3f23bff889175d847e21af06","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"cee8f286794df916553d8d445eac5c323ec5b0f8","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"9100191e5acb2e5ea2313f436667bb5fce129f47","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/ftrace.h","kernel/trace/ftrace.c","kernel/trace/trace.h","kernel/trace/trace_functions.c","kernel/trace/trace_stack.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.15","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/ftrace.h","kernel/trace/ftrace.c","kernel/trace/trace.h","kernel/trace/trace_functions.c","kernel/trace/trace_stack.c"]}],"references":["https://git.kernel.org/stable/c/0124b36a7eac1dd0402146fc6c1f732877b9cd9f","https://git.kernel.org/stable/c/ffe16fe221e25cd1915602e6753c3d3285ed9a98","https://git.kernel.org/stable/c/8f062a6bfeb4b4e18d469a673aec23a7b73c3e8a","https://git.kernel.org/stable/c/29266da8ee1d9be656b1f22460c49538e1930658","https://git.kernel.org/stable/c/177cd8966325f0ffffa3c9381f9e0422019a3973","https://git.kernel.org/stable/c/83fd7eca5ab0d3ac3f23bff889175d847e21af06","https://git.kernel.org/stable/c/cee8f286794df916553d8d445eac5c323ec5b0f8","https://git.kernel.org/stable/c/9100191e5acb2e5ea2313f436667bb5fce129f47"],"weaknesses":[],"ingestedAt":"2026-10-30T12:52:04.348Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90002.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90002","state":"PUBLISHED","datePublished":"2026-09-16T10:33:12.734Z","dateUpdated":"2026-10-30T12:33:46.379Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.780Z"},"containers":{"cna":{"title":"ftrace: Take trace_array reference before accessing its ftrace_ops","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Take trace_array reference before accessing its ftrace_ops\n\nThe trace instance files set_ftrace_filter and set_ftrace_notrace was\nupdated to work with specific trace instances (trace_arrays). The issue is\nthat when these files are opened, there is a small race window where it\nwill use the ftrace_ops from the inode->private pointer to get a reference\nto the trace_array and then take its reference. The problem is that the\nftrace_ops itself could be freed. If the rmdir on the instance happens at\nthe same time the set_ftrace_filter file is opened, the rmdir could have\nalso freed the ftrace_ops and referencing it will cause a use-after-free\nbug and crash the kernel.\n\nInstead, pass in the trace_array as the file private data (NULL for the\ntop level instance), and then pass both the trace_array and the ftrace_ops\nto the ftrace_regex_open() function. If the trace_array is NULL, then it\njust uses the ftrace_ops without the need to take its reference (like\nnormal). If the ftrace_ops is NULL, that is only the case for the top\nlevel instance and the global_ops can be used.\n\nThis allows the trace_array to have its reference incremented before\ntouching the ftrace_ops that could also be freed when the instance is."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"0124b36a7eac1dd0402146fc6c1f732877b9cd9f","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"ffe16fe221e25cd1915602e6753c3d3285ed9a98","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"8f062a6bfeb4b4e18d469a673aec23a7b73c3e8a","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"29266da8ee1d9be656b1f22460c49538e1930658","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"177cd8966325f0ffffa3c9381f9e0422019a3973","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"83fd7eca5ab0d3ac3f23bff889175d847e21af06","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"cee8f286794df916553d8d445eac5c323ec5b0f8","versionType":"git"},{"version":"591dffdade9f07692a7dd3ed16830ec24e901ece","status":"affected","lessThan":"9100191e5acb2e5ea2313f436667bb5fce129f47","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/ftrace.h","kernel/trace/ftrace.c","kernel/trace/trace.h","kernel/trace/trace_functions.c","kernel/trace/trace_stack.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.15","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/ftrace.h","kernel/trace/ftrace.c","kernel/trace/trace.h","kernel/trace/trace_functions.c","kernel/trace/trace_stack.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0124b36a7eac1dd0402146fc6c1f732877b9cd9f"},{"url":"https://git.kernel.org/stable/c/ffe16fe221e25cd1915602e6753c3d3285ed9a98"},{"url":"https://git.kernel.org/stable/c/8f062a6bfeb4b4e18d469a673aec23a7b73c3e8a"},{"url":"https://git.kernel.org/stable/c/29266da8ee1d9be656b1f22460c49538e1930658"},{"url":"https://git.kernel.org/stable/c/177cd8966325f0ffffa3c9381f9e0422019a3973"},{"url":"https://git.kernel.org/stable/c/83fd7eca5ab0d3ac3f23bff889175d847e21af06"},{"url":"https://git.kernel.org/stable/c/cee8f286794df916553d8d445eac5c323ec5b0f8"},{"url":"https://git.kernel.org/stable/c/9100191e5acb2e5ea2313f436667bb5fce129f47"}],"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 reached only by a local open() of an instance set_ftrace_filter/set_ftrace_notrace racing rmdir of that tracing instance under /sys/kernel/tracing/instances; there is no network or adjacent-protocol path into ftrace_filter_open().\nAC:L - The attacker drives both sides: mkdir an instance, open its filter file on one thread, and rmdir it on another. instance_rmdir drops inode locks and kfree()s ftrace_ops before unlinking the files, so the race is retryable with no condition outside attacker control.\nPR:L - ftrace_regex_open()/instance mkdir/rmdir check only LOCKDOWN_TRACEFS (off by default) and DAC, with no capable() call. Android/Perfetto, ChromeOS, and distro tracing-group gid= mounts routinely grant unprivileged users write on /sys/kernel/tracing/instances.\nUI:N - The attacker performs mkdir, concurrent open of set_ftrace_filter/set_ftrace_notrace, and rmdir entirely from their own threads; no victim mount, click, or other-user action is required.\nS:U - The use-after-free is of a kmalloc'd struct ftrace_ops in the host kernel heap; any privilege escalation stays within the kernel's own security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free of heap-allocated ftrace_ops: open() reads ops->private, ops->flags, and ops->func_hash from the freed object, so after slab reclaim/spray those fields become attacker-controlled and yield an arbitrary kernel read.\nI:H - ftrace_ops_init() writes flags, func_hash, and a mutex into the freed object and later mutex_lock()s ops->func_hash->regex_lock; with spray this is an arbitrary-write primitive, and ftrace_ops also carries hijackable function pointers (func, ops_func).\nA:H - Dereferencing the freed ftrace_ops (ops->private, flags, func_hash) on the open-versus-rmdir race reliably oopses or panics the kernel, as described in the fix, and can be re-triggered by repeating instance create/open/rmdir."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:33:46.379Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}