Към съдържанието
Търсене

CVE-2026-63825: Linux

9.8

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се по мрежата, без особени условия, без вход и без действие от потребителя.

    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: gcov: use atomic counter updates to fix concurrent access crashes GCC's GCOV instrumentation can merge global branch counters with loop induction variables as an optimization. In inflate_fast(), the inner copy loops get transformed so that the GCOV counter value is loaded multiple times to compute the loop base address, start index, and end bound. Since GCOV counters are global (not per-CPU), concurrent execution on different CPUs causes the counter to change between loads, producing inconsistent values and out-of-bounds memory writes. The crash manifests during IPComp (IP Payload Compression) processing when inflate_fast() runs concurrently on multiple CPUs: BUG: unable to handle page fault for address: ffffd0a3c0902ffa RIP: inflate_fast+1431 Call Trace: zlib_inflate __deflate_decompress crypto_comp_decompress ipcomp_decompress [xfrm_ipcomp] ipcomp_input [xfrm_ipcomp] xfrm_input At the crash point, the compiler generated three loads from the same global GCOV counter (__gcov0.inflate_fast+216) to compute base, start, and end for an indexed loop. Another CPU modified the counter between loads, making the values inconsistent - the write went 3.4 MB past a 65 KB buffer. Add -fprofile-update=prefer-atomic to CFLAGS_GCOV at the global level in the top-level Makefile, guarded by a try-run compile test. The test compiles a minimal program with and without -fprofile-update=prefer-atomic using the full KBUILD_CFLAGS, then compares undefined symbols in the resulting object files. If prefer-atomic introduces new undefined references (such as __atomic_fetch_add_8 on i386 or __aarch64_ldadd8_relax on arm64 with outline-atomics), the flag is not added -- the kernel does not link against libatomic. On architectures where GCC inlines 64-bit atomic counter updates (x86_64, s390, ...) the test passes and the flag is enabled, preventing the compiler from merging counters with loop i

    Засегнати продукти

    • Linux Linux: 2521f2c228ad750701ba4702484e31d876dbc386 преди 76cb9fde95eba4bd8f06d142a8b8810bf2d09de4; 2521f2c228ad750701ba4702484e31d876dbc386 преди b0f7bd5eeb903a0021a80e9d704814e2a9d3998c; 2521f2c228ad750701ba4702484e31d876dbc386 преди 4575852c23a10abc7648d31e4c12cf79d7391637; 2521f2c228ad750701ba4702484e31d876dbc386 преди 49d893b9cbcfc5802a32e53a64c6c6956670d65b; 2521f2c228ad750701ba4702484e31d876dbc386 преди 5b959c1dbb4522b9e3ac4e26ad638b8784869841; 2521f2c228ad750701ba4702484e31d876dbc386 преди 56cb9b7d96b28a1173a510ab25354b6599ad3a33
    • Linux Linux: 2.6.31; преди 2.6.31; 6.1.191 до 6.1.*; 6.6.160 до 6.6.*; 6.12.114 до 6.12.*; 6.18.38 до 6.18.*; 7.1.3 до 7.1.*; от 7.2 нататък

    История

    • 19 юли 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-63825: Linux | freedomonline.bg