Tracker / CVE-2025-38067
CVE-2025-38067
In the Linux kernel, the following vulnerability has been resolved: rseq: Fix segfault on registration when rseq_cs is non-zero The rseq_cs field is documented as being set to 0 by user-space prior to registration, however this is not currently enforced by the kernel. This can result in a segfault on return to user-space if the value stored in the rseq_cs field doesn't point to a valid struct rseq_cs. The correct solution to this would be to fail the rseq registration when the rseq_cs field is non-zero. However, some older versions of glibc will reuse the rseq area of previous threads without clearing the rseq_cs field and will also terminate the process if the rseq registration fails in a secondary thread. This wasn't caught in testing because in this case the leftover rseq_cs does point to a valid struct rseq_cs. What we can do is clear the rseq_cs field on registration when it's non-zero which will prevent segfaults on registration and won't break the glibc versions that reuse rseq areas on thread creation.
Affected products and versions
| debian | debian_linux |
|---|---|
| linux | linux_kernel · 4.18 → 5.10.240 |
| linux | linux_kernel · 5.11 → 5.15.189 |
| linux | linux_kernel · 5.16 → 6.1.146 |
| linux | linux_kernel · 6.13 → 6.14.9 |
| linux | linux_kernel · 6.2 → 6.6.99 |
| linux | linux_kernel · 6.7 → 6.12.39 |