CVE-2025-38233: powerpc64/ftrace: fix clobbered r15 during livepatching
In the Linux kernel, the following vulnerability has been resolved:
powerpc64/ftrace: fix clobbered r15 during livepatching
While r15 is clobbered always with PPCFTRACEOUTOFLINE, it is not restored in livepatch sequence leading to not so obvious fails like below:
BUG: Unable to handle kernel data access on write at 0xc0000000000f9078 Faulting instruction address: 0xc0000000018ff958 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790 REGS: c00000005f2e7790 TRAP: 0300 Tainted: G K (6.14.0+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 2822880b XER: 20040000 CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1 GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488 GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000 GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070 GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88 GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000 GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078 ... Call Trace: checkheapobject+0x34/0x390 (unreliable) mutexunlockslowpath.isra.0+0xe4/0x230 seqreaditer+0x430/0xa90 procregreaditer+0xa4/0x200 vfsread+0x41c/0x510 ksysread+0xa4/0x190 systemcallexception+0x1d0/0x440 systemcallvectoredcommon+0x15c/0x2ec
Fix it by restoring r15 always.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Linux kernelto a version that resolves this vulnerability.Patch powerpc64/ftrace: fix clobbered r15 during livepatching - Configuration
Fix the livepatching path so that r15 is always restored (the vulnerability describes r15 being clobbered during livepatching, leading to kernel access of bad area).
Linux kernel livepatching (PowerPC64 ftrace) Restore r15 during livepatch sequence = Always restore r15
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38233?
CVE-2025-38233 does not have a publicly assigned severity level but addresses a critical issue in the Linux kernel.
How do I fix CVE-2025-38233?
To fix CVE-2025-38233, you should update your Linux kernel to the latest fixed version.
Which versions of Linux kernel are affected by CVE-2025-38233?
CVE-2025-38233 affects Linux kernel versions starting from 6.14.0.
What impacts could CVE-2025-38233 have on system performance?
CVE-2025-38233 could lead to system crashes or unexpected behavior during livepatching.
Is there a workaround for CVE-2025-38233?
There are no known workarounds for CVE-2025-38233; updating to a patched kernel is recommended.