CVE-2023-52598

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().

Affected Software

VendorProductVersion RangeStatus
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 6ccf904aac0292e1f6b1a1be6c407c414f7cf713affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 6d0822f2cc9b153bf2df49a84599195a2e0d21a8affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 856caf2730ea18cb39e95833719c02a02447dc0aaffected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 28a1f492cb527f64593457a0a0f0d809b3f36c25affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 7a4d6481fbdd661f9e40e95febb95e3dee82bad3affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 02c6bbfb08bad78dd014e24c7b893723c15ec7a1affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < bdce67df7f12fb0409fbc604ce7c4254703f56d4affected
LinuxLinux9977e886cbbc758b4b601a160b5825ba573b5ca8 < 8b13601d19c541158a6e18b278c00ba69ae37829affected
LinuxLinux4.3affected
LinuxLinux0 < 4.3unaffected
LinuxLinux4.19.307 <= 4.19.*unaffected
LinuxLinux5.4.269 <= 5.4.*unaffected
LinuxLinux5.10.210 <= 5.10.*unaffected
LinuxLinux5.15.149 <= 5.15.*unaffected
LinuxLinux6.1.77 <= 6.1.*unaffected
LinuxLinux6.6.16 <= 6.6.*unaffected
LinuxLinux6.7.4 <= 6.7.*unaffected
LinuxLinux6.8 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References