CVE-2023-52598 s390/ptrace: handle setting of fpc register correctly
A flaw in the Linux kernel s390 ptrace implementation allows register corruption, potentially enabling privilege escalation or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-52598?
CVE-2023-52598 is a high-severity memory corruption vulnerability in Linux kernel, published on 6 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
s390/ptrace: handle setting of fpc register correctly
If the content of the floating point control (fpc) register of a traced process is modified with the ptrace interface the new value is tested for validity by temporarily loading it into the fpc register.
This may lead to corruption of the fpc register of the tracing process: if an interrupt happens while the value is temporarily loaded into the fpc register, and within interrupt context floating point or vector registers are used, the current fp/vx registers are saved with save_fpu_regs() assuming they belong to user space and will be loaded into fp/vx registers when returning to user space.
test_fp_ctl() restores the original user space fpc register value, however it will be discarded, when returning to user space.
In result the tracer will incorrectly continue to run with the value that was supposed to be used for the traced process.
Fix this by saving fpu register contents with save_fpu_regs() before using test_fp_ctl().
Weakness: CWE-125
Which versions are affected by CVE-2023-52598?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52598?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-52598 being exploited?
There is no known exploitation of CVE-2023-52598 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-52598, DEBIAN-CVE-2023-52598, GHSA-c4rp-h96r-7xm9, UBUNTU-CVE-2023-52598.