CVSS 5.5 · Medium EPSS 0,12%
Kerentanan pada linux kernel. Skor CVSS 3.1 5.5 (Medium) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: x86/kexec: Disable KCOV instrumentation after load_segments() The load_segments() function changes segment registers, invalidating GS base (which KCOV relies on for per-cpu data). When CONFIG_KCOV is enabled, any subsequent instrumented C code call (e.g. native_gdt_invalidate()) begins crashing the kernel in an endless loop. To reproduce the problem, it's sufficient to do kexec on a KCOV-instrumented kernel: $ kexec -l /boot/otherKernel $ kexec -e The real-world context for this problem is enabling crash dump collection in syzkaller. For this, the tool loads a panic kernel before fuzzing and then calls makedumpfile after the panic. This workflow requires both CONFIG_KEXEC and CONFIG_KCOV to be enabled simultaneously. Adding safeguards directly to the KCOV fast-path (__sanitizer_cov_trace_pc()) is also undesirable as it would introduce an extra performance overhead. Disabling instrumentation for the individual functions would be too fragile, so disable KCOV instrumentation for the entire machine_kexec_64.c and physaddr.c. If coverage-guided fuzzing ever needs these components in the future, other approaches should be considered. The problem is not relevant for 32 bit kernels as CONFIG_KCOV is not supported there. [ bp: Space out comment for better readability. ]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 6.6 hingga sebelum 6.18.22 |
| linux | linux kernel | Versi 6.19 hingga sebelum 6.19.12 |
| linux | linux kernel | Versi 7.0 rc1 |
| linux | linux kernel | Versi 7.0 rc2 |
| linux | linux kernel | Versi 7.0 rc3 |
| linux | linux kernel | Versi 7.0 rc4 |
| linux | linux kernel | Versi 7.0 rc5 |
| linux | linux kernel | Versi 7.0 rc6 |