CVE-2023-53491

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Now that the function attribute is available, let's start using\nit.\n\nCallers of boot_init_stack_canary need to use this function attribute\nunless they're compiled with -fno-stack-protector, otherwise the canary\nstored in the stack slot of the caller will differ upon the call to\nboot_init_stack_canary. This will lead to a call to __stack_chk_fail()\nthen panic."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - There is no network-reachable path to this code \u2014 `start_kernel()` and powerpc `start_secondary()` are kernel-initialization and CPU-bring-up entry points invoked from architecture assembly (`head_64.S`, `head_44x.S`, `head_85xx.S`) and from `__cpu_up()` during hotplug/resume, all of which are local to the machine. The vulnerable component is therefore only reachable via local system context (boot, CPU hotplug, suspend/resume).\nAC:L - On a kernel built with `CONFIG_STACKPROTECTOR=y` and a toolchain that instruments these functions, the stale-canary comparison mismatches deterministically on every boot and every secondary-CPU bring-up \u2014 there is no race, no memory-layout dependency, and no timing window to win. The failure reproduces reliably and at will, so no condition beyond the attacker's control gates it.\nPR:N - The panic in `start_kernel()` occurs during kernel initialization, before `init(1)` and before any user account, credential check, or namespace exists; the `start_secondary()` path is likewise entered from the secondary-CPU assembly stub with no privilege gate. No authentication or privilege of any kind is involved in reaching the faulty canary check.\nUI:N - No victim action is needed \u2014 the condition is hit automatically as part of normal boot and CPU bring-up. Nothing must be mounted, opened, or clicked.\nS:U - The `__stack_chk_fail()` \u2192 `panic()` sequence is entirely contained within the kernel's own security authority, affecting only the kernel that executed it. No VM, IOMMU, or sandbox boundary is crossed.\nC:N - `__stack_chk_fail()` is a fail-stop check: it halts the system rather than reading or exposing memory, and no out-of-bounds read, uninitialized data, or attacker-retrievable kernel state is produced. Per the pure-crash guidance, there is no information disclosure.\nI:N - Nothing is written out of bounds and no object is corrupted \u2014 the canary in the caller's frame is intact; the comparison is a false positive caused by the canary *source* changing underneath it. There is no write primitive and no control-flow hijack potential.\nA:H - The outcome is `panic(\"stack-protector: Kernel stack is corrupted in: start_kernel\")`, i.e. an unbootable system, or a panic during secondary-CPU bring-up via `start_secondary()` on hotplug/resume. This is total, unrecoverable loss of availability for the affected machine."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/powerpc/kernel/smp.c", "include/linux/compiler_attributes.h", "init/main.c"], "versions": [{"version": "420594296838fdc9a674470d710cda7d1487f9f4", "lessThan": "5a7e8f89cdee16db705905a5b1ce2100b13dd63e", "status": "affected", "versionType": "git"}, {"version": "420594296838fdc9a674470d710cda7d1487f9f4", "lessThan": "25e73018b4093e0cfbcec5dc4a4bb86d0b69ed56", "status": "affected", "versionType": "git"}, {"version": "420594296838fdc9a674470d710cda7d1487f9f4", "lessThan": "514ca14ed5444b911de59ed3381dfd195d99fe4b", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/powerpc/kernel/smp.c", "include/linux/compiler_attributes.h", "init/main.c"], "versions": [{"version": "2.6.30", "status": "affected"}, {"version": "0", "lessThan": "2.6.30", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.4.4", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.5", "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": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.4.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.5"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/5a7e8f89cdee16db705905a5b1ce2100b13dd63e"}, {"url": "https://git.kernel.org/stable/c/25e73018b4093e0cfbcec5dc4a4bb86d0b69ed56"}, {"url": "https://git.kernel.org/stable/c/514ca14ed5444b911de59ed3381dfd195d99fe4b"}], "title": "start_kernel: Add __no_stack_protector function attribute", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2023-53491", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-15T21:34:51.888438Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-15T21:41:28.874Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2023-53491", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-15T21:34:51.888438Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-15T21:34:52.547Z"}}], "cna": {"title": "start_kernel: Add __no_stack_protector function attribute", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.5, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - There is no network-reachable path to this code \u2014 `start_kernel()` and powerpc `start_secondary()` are kernel-initialization and CPU-bring-up entry points invoked from architecture assembly (`head_64.S`, `head_44x.S`, `head_85xx.S`) and from `__cpu_up()` during hotplug/resume, all of which are local to the machine. The vulnerable component is therefore only reachable via local system context (boot, CPU hotplug, suspend/resume).\nAC:L - On a kernel built with `CONFIG_STACKPROTECTOR=y` and a toolchain that instruments these functions, the stale-canary comparison mismatches deterministically on every boot and every secondary-CPU bring-up \u2014 there is no race, no memory-layout dependency, and no timing window to win. The failure reproduces reliably and at will, so no condition beyond the attacker's control gates it.\nPR:N - The panic in `start_kernel()` occurs during kernel initialization, before `init(1)` and before any user account, credential check, or namespace exists; the `start_secondary()` path is likewise entered from the secondary-CPU assembly stub with no privilege gate. No authentication or privilege of any kind is involved in reaching the faulty canary check.\nUI:N - No victim action is needed \u2014 the condition is hit automatically as part of normal boot and CPU bring-up. Nothing must be mounted, opened, or clicked.\nS:U - The `__stack_chk_fail()` \u2192 `panic()` sequence is entirely contained within the kernel's own security authority, affecting only the kernel that executed it. No VM, IOMMU, or sandbox boundary is crossed.\nC:N - `__stack_chk_fail()` is a fail-stop check: it halts the system rather than reading or exposing memory, and no out-of-bounds read, uninitialized data, or attacker-retrievable kernel state is produced. Per the pure-crash guidance, there is no information disclosure.\nI:N - Nothing is written out of bounds and no object is corrupted \u2014 the canary in the caller's frame is intact; the comparison is a false positive caused by the canary *source* changing underneath it. There is no write primitive and no control-flow hijack potential.\nA:H - The outcome is `panic(\"stack-protector: Kernel stack is corrupted in: start_kernel\")`, i.e. an unbootable system, or a panic during secondary-CPU bring-up via `start_secondary()` on hotplug/resume. 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This was fixed in\ngcc-11. Now that the function attribute is available, let's start using\nit.\n\nCallers of boot_init_stack_canary need to use this function attribute\nunless they're compiled with -fno-stack-protector, otherwise the canary\nstored in the stack slot of the caller will differ upon the call to\nboot_init_stack_canary. This will lead to a call to __stack_chk_fail()\nthen panic."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.189", "versionStartIncluding": "2.6.30"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.4.4", "versionStartIncluding": "2.6.30"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.5", "versionStartIncluding": "2.6.30"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-03T10:54:55.571Z"}}}, "cveMetadata": {"cveId": "CVE-2023-53491", "state": "PUBLISHED", "dateUpdated": "2026-10-15T21:41:28.874Z", "dateReserved": "2025-10-01T11:39:39.403Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2025-10-01T11:45:43.101Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

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{"bugzilla": {"description": "kernel: start_kernel: Add __no_stack_protector function attribute", "id": "2400809", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2400809"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2023-53491", "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": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:rhivos:1", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat In-Vehicle Operating System 1"}], "public_date": "2025-10-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2023-53491\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53491\nhttps://lore.kernel.org/linux-cve-announce/2025100123-CVE-2023-53491-2d8b@gregkh/T"], "threat_severity": "Moderate"}

{"created": "2025-10-02T08:38:40.972534+00:00", "updated": "2025-10-02T08:38:40.972666+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}