s390/ptrace: handle setting of fpc register correctly
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
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().
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
4.3
References 8
git.kernel.org
- stable/c/6ccf904aac0292e1f6b1a1be6c407c414f7cf713
- stable/c/6d0822f2cc9b153bf2df49a84599195a2e0d21a8
- stable/c/856caf2730ea18cb39e95833719c02a02447dc0a
- stable/c/28a1f492cb527f64593457a0a0f0d809b3f36c25
- stable/c/7a4d6481fbdd661f9e40e95febb95e3dee82bad3
- stable/c/02c6bbfb08bad78dd014e24c7b893723c15ec7a1
- stable/c/bdce67df7f12fb0409fbc604ce7c4254703f56d4
- stable/c/8b13601d19c541158a6e18b278c00ba69ae37829