{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53491","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-10-01T11:39:39.403Z","datePublished":"2025-10-01T11:45:43.101Z","dateUpdated":"2026-08-05T09:14:23.246Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T09:14:23.246Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nstart_kernel: Add __no_stack_protector function attribute\n\nBack during the discussion of\ncommit a9a3ed1eff36 (\"x86: Fix early boot crash on gcc-10, third try\")\nwe discussed the need for a function attribute to control the omission\nof stack protectors on a per-function basis; at the time Clang had\nsupport for no_stack_protector but GCC did not. 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."}],"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 — `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 — 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 — 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()` → `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 — 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":"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":"6.4.4","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":"6.4.4"},{"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/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"}}}}