{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38233", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.996Z", "datePublished": "2025-07-04T13:37:46.293Z", "dateUpdated": "2026-08-05T12:00:33.319Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:33.319Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc64/ftrace: fix clobbered r15 during livepatching\n\nWhile r15 is clobbered always with PPC_FTRACE_OUT_OF_LINE, it is\nnot restored in livepatch sequence leading to not so obvious fails\nlike below:\n\n BUG: Unable to handle kernel data access on write at 0xc0000000000f9078\n Faulting instruction address: 0xc0000000018ff958\n Oops: Kernel access of bad area, sig: 11 [#1]\n ...\n NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790\n REGS: c00000005f2e7790 TRAP: 0300 Tainted: G K (6.14.0+)\n MSR: 8000000000009033 CR: 2822880b XER: 20040000\n CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1\n GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488\n GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d\n GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000\n GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070\n GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000\n GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88\n GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000\n GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078\n ...\n Call Trace:\n check_heap_object+0x34/0x390 (unreliable)\n __mutex_unlock_slowpath.isra.0+0xe4/0x230\n seq_read_iter+0x430/0xa90\n proc_reg_read_iter+0xa4/0x200\n vfs_read+0x41c/0x510\n ksys_read+0xa4/0x190\n system_call_exception+0x1d0/0x440\n system_call_vectored_common+0x15c/0x2ec\n\nFix it by restoring r15 always." } ], "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 corrupted register is consumed by ordinary kernel code paths entered through local syscalls — the reported oops comes from a plain read(2) on a procfs file (`ksys_read → vfs_read → seq_read_iter`). No network protocol handler is inherently involved; reaching the defect requires executing kernel code on the machine.\nAC:L - With a livepatch active, the missing `REST_GPR(15, r1)` executes on 100% of calls to any patched function — no race, no memory-layout dependency, no timing window. The enabling configuration (ppc64le with `PPC_FTRACE_OUT_OF_LINE` + `LIVEPATCH`) is the default shipping state on enterprise ppc64le distros that offer live patching.\nPR:L - Triggering needs nothing more than invoking a syscall that reaches a livepatched function; the reproducer is an unprivileged `read()` on /proc. The livepatch itself is loaded by the administrator as routine maintenance, not as an attacker step, so the attacker only needs an ordinary local account.\nUI:N - Once a livepatch is applied — the normal steady state of a live-patched server — no victim action of any kind is required; the attacker simply calls into a patched function.\nS:U - The clobbered non-volatile register corrupts the kernel's own execution state within the same security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - The caller chain resumes with r15 silently replaced by a kernel `.text` stub address, so any function using r15 as a pointer, index, or length operates on corrupted state — on read/usercopy paths (`seq_read_iter`, `check_heap_object` in the reported trace) this can steer kernel memory into a user buffer, and the injected value itself is a live kernel text address that defeats KASLR if it reaches userspace.\nI:H - This is genuine kernel memory corruption with write effect — the reported failure is a faulting *store* to an address derived from the clobbered register, from inside `__mutex_unlock_slowpath` operating on a corrupt mutex pointer. Corrupting a callee-saved register in arbitrary kernel functions yields uncontrolled writes and corrupted locking/data structures that can be leveraged for control-flow-relevant damage.\nA:H - The demonstrated result is an immediate kernel oops (\"Unable to handle kernel data access on write\", sig 11), and because the corruption recurs on every call to a patched function it is trivially repeatable until the system panics or hangs on corrupted lock state." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/kernel/trace/ftrace_entry.S" ], "versions": [ { "version": "eec37961a56aa4f3fe1c33ffd48eec7d1bb0c009", "lessThan": "a9212bf5ca640232254b31330e86272fe4073bc9", "status": "affected", "versionType": "git" }, { "version": "eec37961a56aa4f3fe1c33ffd48eec7d1bb0c009", "lessThan": "cb5b691f8273432297611863ac142e17119279e0", "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/trace/ftrace_entry.S" ], "versions": [ { "version": "6.13", "status": "affected" }, { "version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.4", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "6.13", "versionEndExcluding": "6.15.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a9212bf5ca640232254b31330e86272fe4073bc9" }, { "url": "https://git.kernel.org/stable/c/cb5b691f8273432297611863ac142e17119279e0" } ], "title": "powerpc64/ftrace: fix clobbered r15 during livepatching", "x_generator": { "engine": "bippy-1.2.0" } } } }