CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
5.0%
In the Linux kernel, the following vulnerability has been resolved:
bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD
[Changes from V1:
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.
git.kernel.org/stable/c/009367099eb61a4fc2af44d4eb06b6b4de7de6db
git.kernel.org/stable/c/3364c2ed1c241989847f19cf83e3db903ce689e3
git.kernel.org/stable/c/7e5471b5efebc30dd0bc035cda86693a5c73d45f
git.kernel.org/stable/c/a21d76bd0b0d39518e9a4c19f6cf7c042a974aff
git.kernel.org/stable/c/b694989bb13ed5f166e633faa1eb0f21c6d261a6
git.kernel.org/stable/c/ff941a8449e712eaf7efca1a13bfb9afd3d99fc2
security-tracker.debian.org/tracker/CVE-2024-42161