{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90002", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.780Z", "datePublished": "2026-09-16T10:33:12.734Z", "dateUpdated": "2026-10-21T12:49:23.283Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:49:23.283Z" }, "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." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "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" ], "versions": [ { "version": "591dffdade9f07692a7dd3ed16830ec24e901ece", "lessThan": "29266da8ee1d9be656b1f22460c49538e1930658", "status": "affected", "versionType": "git" }, { "version": "591dffdade9f07692a7dd3ed16830ec24e901ece", "lessThan": "177cd8966325f0ffffa3c9381f9e0422019a3973", "status": "affected", "versionType": "git" }, { "version": "591dffdade9f07692a7dd3ed16830ec24e901ece", "lessThan": "83fd7eca5ab0d3ac3f23bff889175d847e21af06", "status": "affected", "versionType": "git" }, { "version": "591dffdade9f07692a7dd3ed16830ec24e901ece", "lessThan": "cee8f286794df916553d8d445eac5c323ec5b0f8", "status": "affected", "versionType": "git" }, { "version": "591dffdade9f07692a7dd3ed16830ec24e901ece", "lessThan": "9100191e5acb2e5ea2313f436667bb5fce129f47", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "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" ], "versions": [ { "version": "3.15", "status": "affected" }, { "version": "0", "lessThan": "3.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "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": "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" } ] } ] } ], "references": [ { "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" } ], "title": "ftrace: Take trace_array reference before accessing its ftrace_ops", "x_generator": { "engine": "bippy-1.2.0" } } } }