CVE-2026-64451

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64451", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.788Z", "datePublished": "2026-07-25T08:51:21.020Z", "dateUpdated": "2026-08-17T04:55:55.128Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:55:55.128Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix NULL pointer dereference in func_set_flag()\n\nfunc_set_flag() dereferences tr->current_trace_flags before verifying\nthat the current tracer is actually the function tracer. When the active\ntracer has been switched away from \"function\" (e.g., to \"wakeup_rt\"),\ntr->current_trace_flags can be NULL, leading to a NULL pointer\ndereference and kernel crash.\n\nThe call chain that triggers this is:\n\n trace_options_write()\n -> __set_tracer_option()\n -> trace->set_flag() /* func_set_flag */\n\nIn func_set_flag(), the first operation is:\n\n if (!!set == !!(tr->current_trace_flags->val & bit))\n\nThis dereferences tr->current_trace_flags unconditionally. The safety\ncheck that guards against a non-function tracer:\n\n if (tr->current_trace != &function_trace)\n return 0;\n\nis placed *after* the dereference, which is too late.\n\nThis was observed with the following crash dump:\n\n BUG: unable to handle page fault at 0000000000000000\n RIP: func_set_flag+0xd\n\n Call Trace:\n __set_tracer_option+0x27\n trace_options_write+0x75\n vfs_write+0x12a\n ksys_write+0x66\n do_syscall_64+0x5b\n\n RIP: ffffffff914c973d RSP: ff67ec88b01dfdf0 RFLAGS: 00010202\n RAX: 0000000000000000 RBX: ff3a826e80354580 RCX: 0000000000000001\n RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff93918080\n\nThe disassembly confirms the fault:\n\n func_set_flag+0: mov 0x1f08(%rdi), %rax ; RAX = tr->current_trace_flags = NULL\n func_set_flag+13: mov (%rax), %eax ; page fault: dereference NULL\n\nAt the time of the crash:\n tr->current_trace_flags = 0x0 (NULL)\n tr->current_trace = wakeup_rt_tracer (not function_trace)\n\nThe scenario is that a process opens a function tracer option file (such\nas \"func_stack_trace\"), then the current tracer is switched to another\ntracer (e.g., \"wakeup_rt\"), which sets current_trace_flags to NULL. When\nthe process subsequently writes to the option file, func_set_flag() is\ninvoked and crashes on the NULL dereference.\n\nFix this by moving the current_trace check before the\ncurrent_trace_flags dereference, so that func_set_flag() returns early\nwhen the function tracer is not active."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace_functions.c"], "versions": [{"version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a", "lessThan": "69f17ac132a38974cf1defb480cef6b79d1ab768", "status": "affected", "versionType": "git"}, {"version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a", "lessThan": "c3e94604675e3db186111b8942650d86577df9b0", "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_functions.c"], "versions": [{"version": "6.19", "status": "affected"}, {"version": "0", "lessThan": "6.19", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "6.19", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/69f17ac132a38974cf1defb480cef6b79d1ab768"}, {"url": "https://git.kernel.org/stable/c/c3e94604675e3db186111b8942650d86577df9b0"}], "title": "tracing: Fix NULL pointer dereference in func_set_flag()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/trace/trace_functions.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "69f17ac132a38974cf1defb480cef6b79d1ab768", "status": "affected", "version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a", "versionType": "git"}, {"lessThan": "c3e94604675e3db186111b8942650d86577df9b0", "status": "affected", "version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/trace/trace_functions.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.19"}, {"lessThan": "6.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42", "versionEndExcluding": "7.1.4", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*", "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*", "matchCriteriaId": "1FC0D50D-9D58-4947-A197-A5A3FF07E7E3", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix NULL pointer dereference in func_set_flag()\n\nfunc_set_flag() dereferences tr->current_trace_flags before verifying\nthat the current tracer is actually the function tracer. When the active\ntracer has been switched away from \"function\" (e.g., to \"wakeup_rt\"),\ntr->current_trace_flags can be NULL, leading to a NULL pointer\ndereference and kernel crash.\n\nThe call chain that triggers this is:\n\n trace_options_write()\n -> __set_tracer_option()\n -> trace->set_flag() /* func_set_flag */\n\nIn func_set_flag(), the first operation is:\n\n if (!!set == !!(tr->current_trace_flags->val & bit))\n\nThis dereferences tr->current_trace_flags unconditionally. The safety\ncheck that guards against a non-function tracer:\n\n if (tr->current_trace != &function_trace)\n return 0;\n\nis placed *after* the dereference, which is too late.\n\nThis was observed with the following crash dump:\n\n BUG: unable to handle page fault at 0000000000000000\n RIP: func_set_flag+0xd\n\n Call Trace:\n __set_tracer_option+0x27\n trace_options_write+0x75\n vfs_write+0x12a\n ksys_write+0x66\n do_syscall_64+0x5b\n\n RIP: ffffffff914c973d RSP: ff67ec88b01dfdf0 RFLAGS: 00010202\n RAX: 0000000000000000 RBX: ff3a826e80354580 RCX: 0000000000000001\n RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff93918080\n\nThe disassembly confirms the fault:\n\n func_set_flag+0: mov 0x1f08(%rdi), %rax ; RAX = tr->current_trace_flags = NULL\n func_set_flag+13: mov (%rax), %eax ; page fault: dereference NULL\n\nAt the time of the crash:\n tr->current_trace_flags = 0x0 (NULL)\n tr->current_trace = wakeup_rt_tracer (not function_trace)\n\nThe scenario is that a process opens a function tracer option file (such\nas \"func_stack_trace\"), then the current tracer is switched to another\ntracer (e.g., \"wakeup_rt\"), which sets current_trace_flags to NULL. When\nthe process subsequently writes to the option file, func_set_flag() is\ninvoked and crashes on the NULL dereference.\n\nFix this by moving the current_trace check before the\ncurrent_trace_flags dereference, so that func_set_flag() returns early\nwhen the function tracer is not active."}], "id": "CVE-2026-64451", "lastModified": "2026-09-03T15:29:27.130", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-07-25T10:17:30.013", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/69f17ac132a38974cf1defb480cef6b79d1ab768"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/c3e94604675e3db186111b8942650d86577df9b0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: tracing: Fix NULL pointer dereference in func_set_flag()", "id": "2507279", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507279"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["A flaw was found in the Linux kernel's tracing subsystem. A local user, by manipulating function tracer options, can trigger a NULL pointer dereference in the func_set_flag() function. This vulnerability occurs when the active tracer is switched away from the function tracer while a process has an option file for it open, leading to a kernel crash and a denial of service."], "name": "CVE-2026-64451", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64451\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64451\nhttps://lore.kernel.org/linux-cve-announce/2026072541-CVE-2026-64451-1842@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[76680d0d2825900f23bf35290ab2b80bdf3a8e4a,69f17ac132a38974cf1defb480cef6b79d1ab768)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[76680d0d2825900f23bf35290ab2b80bdf3a8e4a,c3e94604675e3db186111b8942650d86577df9b0)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2-rc3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-25T19:15:03.262872+00:00", "updated": "2026-08-03T18:45:17.771826+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}