{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90013", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.781Z", "datePublished": "2026-09-16T10:33:20.136Z", "dateUpdated": "2026-10-21T12:49:24.882Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:49:24.882Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Take trace_array reference when opening options file\n\nThe options files do not take the trace_array reference for the options\nthey represent. This could cause a use-after-free kernel crash if one of\nthese files is opened by one task and another task removes the instance\nthat the option is for. Because it doesn't take a reference upon opening,\nit will not stop the removal which will free the options descriptor that\nis being used.\n\nAs the options are somewhat dynamic in their creation at boot up, each\nfile represents a flag in the trace_array. The trace_array has an array of\nindexes to represent each of these flags that is stored in the\ntrace_flags_index array. The address of the index array element is used to\npass to the inode->i_private pointer. Then that element is read which\nholds the index (which represents the flag) and then the index is used to\ncalculate the trace_array descriptor from its trace_flags_index array.\n\nOne issue is that the index element can not be referenced until the\ntrace_array's reference is taken. To handle this, create a new helper\nfunction called: trace_array_options_get() that will iterate all the\nexisting trace_arrays in the ftrace_trace_arrays list (under the\ntrace_types_lock), and compare the passed in address of the index element\nwith the entire array of the trace_array's trace_flags_index array.\nIf it matches, then up the corresponding trace_array's reference and\nreturn." } ], "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 via local tracefs: open() of an instance options file (tracing_open_generic -> trace_options_core_read/write) then rmdir of that instance (__remove_instance). No network, adjacent-radio, or physical-device path reaches get_tr_index() or the freed trace_array.\nAC:L - The attacker fully controls both sides: open an instance options file (no trace_array ref), rmdir the instance so __remove_instance kfree()s the trace_array, then read/write the still-open fd. That sequence is deterministic and retryable; CONFIG_TRACING with instances is standard, not a rare config.\nPR:L - tracing_open_generic() and instance mkdir/rmdir enforce only LOCKDOWN_TRACEFS and DAC (options 0640, dirs 0750) with no capable() gate. Android/Perfetto, ChromeOS, and gid=/uid= tracing mounts routinely delegate this to unprivileged tracing accounts, matching CVE-2026-74606 and CVE-2026-89747.\nUI:N - The attacker mkdir()s their own tracing instance, opens options, rmdir()s the instance, and reads or writes the fd themselves. No victim mount, click, or cooperating process is required.\nS:U - The use-after-free corrupts a kernel trace_array in the tracing subsystem on the same host. It can yield local privilege escalation but does not cross a VM, IOMMU, or other security authority.\nC:H - After rmdir, get_tr_index() reads the freed trace_flags_index byte and reconstructs a trace_array, then trace_options_core_read() loads tr->trace_flags. Reclaiming that slab lets the attacker control the object and obtain an arbitrary kernel read, which kernel CNA guidance scores High for UAF.\nI:H - trace_options_core_write() calls set_tracer_flag() on the freed/reused trace_array, including tr->current_trace->flag_changed and writes to tr->trace_flags and related tracing state. Heap spraying that object yields an arbitrary kernel write and control-flow hijack primitive.\nA:H - Dereferencing the kfree()d trace_array in get_tr_index()/trace_options_core_read() oopses or panics the kernel, which the fix describes as a use-after-free kernel crash. The attacker can retrigger that crash at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/trace.c" ], "versions": [ { "version": "577b785f55168d5acb3d123ba41bfe8d7981e044", "lessThan": "8cc9c5a8c559d655c32d2190486e89574c14ff52", "status": "affected", "versionType": "git" }, { "version": "577b785f55168d5acb3d123ba41bfe8d7981e044", "lessThan": "97ceaffbd672449ad7ead5ae8788dce16374b0c1", "status": "affected", "versionType": "git" }, { "version": "577b785f55168d5acb3d123ba41bfe8d7981e044", "lessThan": "d0f37d77b9b4b241e0b30ef2562f6353cbda3bec", "status": "affected", "versionType": "git" }, { "version": "577b785f55168d5acb3d123ba41bfe8d7981e044", "lessThan": "64a41f4a9a968f54f3792399aa4d2a9fdb23b0a5", "status": "affected", "versionType": "git" }, { "version": "577b785f55168d5acb3d123ba41bfe8d7981e044", "lessThan": "f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/trace.c" ], "versions": [ { "version": "2.6.30", "status": "affected" }, { "version": "0", "lessThan": "2.6.30", "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": "2.6.30", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8cc9c5a8c559d655c32d2190486e89574c14ff52" }, { "url": "https://git.kernel.org/stable/c/97ceaffbd672449ad7ead5ae8788dce16374b0c1" }, { "url": "https://git.kernel.org/stable/c/d0f37d77b9b4b241e0b30ef2562f6353cbda3bec" }, { "url": "https://git.kernel.org/stable/c/64a41f4a9a968f54f3792399aa4d2a9fdb23b0a5" }, { "url": "https://git.kernel.org/stable/c/f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73" } ], "title": "tracing: Take trace_array reference when opening options file", "x_generator": { "engine": "bippy-1.2.0" } } } }