Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD [Changes from V1: - Use a default branch in the switch statement to initialize `val'.] GCC warns that `val' may be used uninitialized in the BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as: [...] unsigned long long val; \ [...] \ switch (__CORE_RELO(s, field, BYTE_SIZE)) { \ case 1: val = *(const unsigned char *)p; break; \ case 2: val = *(const unsigned short *)p; break; \ case 4: val = *(const unsigned int *)p; break; \ case 8: val = *(const unsigned long long *)p; break; \ } \ [...] val; \ } \ This patch adds a default entry in the switch statement that sets `val' to zero in order to avoid the warning, and random values to be used in case __builtin_preserve_field_info returns unexpected values for BPF_FIELD_BYTE_SIZE. Tested in bpf-next master. No regressions.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
ee26dade0e3bcd8a34ae7520e373fb69365fce7a to < b694989bb13ed5f166e633faa1eb0f21c6d261a6affectedee26dade0e3bcd8a34ae7520e373fb69365fce7a to < 3364c2ed1c241989847f19cf83e3db903ce689e3affectedee26dade0e3bcd8a34ae7520e373fb69365fce7a to < a21d76bd0b0d39518e9a4c19f6cf7c042a974affaffectedee26dade0e3bcd8a34ae7520e373fb69365fce7a to < 7e5471b5efebc30dd0bc035cda86693a5c73d45faffectedee26dade0e3bcd8a34ae7520e373fb69365fce7a to < ff941a8449e712eaf7efca1a13bfb9afd3d99fc2affectedee26dade0e3bcd8a34ae7520e373fb69365fce7a to < 009367099eb61a4fc2af44d4eb06b6b4de7de6dbaffected
Linux Linux
Default version status: affected
5.5affected0 to < 5.5unaffected5.10.222 to ≤ 5.10.*unaffected5.15.163 to ≤ 5.15.*unaffected6.1.98 to ≤ 6.1.*unaffected6.6.39 to ≤ 6.6.*unaffected6.9.9 to ≤ 6.9.*unaffected6.10 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/b694989bb13ed5f166e633faa1eb0f21c6d261a6 ↗
- https://git.kernel.org/stable/c/3364c2ed1c241989847f19cf83e3db903ce689e3 ↗
- https://git.kernel.org/stable/c/a21d76bd0b0d39518e9a4c19f6cf7c042a974aff ↗
- https://git.kernel.org/stable/c/7e5471b5efebc30dd0bc035cda86693a5c73d45f ↗
- https://git.kernel.org/stable/c/ff941a8449e712eaf7efca1a13bfb9afd3d99fc2 ↗
- https://git.kernel.org/stable/c/009367099eb61a4fc2af44d4eb06b6b4de7de6db ↗
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html ↗