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.
Metrics
Affected Vendors & Products
Tue, 05 Nov 2024 10:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
|
Wed, 25 Sep 2024 16:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
cvssV3_1
|
cvssV3_1
|
Wed, 11 Sep 2024 18:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
|
Wed, 11 Sep 2024 13:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
|
Sat, 17 Aug 2024 02:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Weaknesses | CWE-457 |

Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-06-19T12:56:37.768Z
Reserved: 2024-07-29T15:50:41.196Z
Link: CVE-2024-42161

Updated: 2024-08-02T04:54:32.572Z

Status : Modified
Published: 2024-07-30T08:15:07.447
Modified: 2024-11-21T09:33:43.733
Link: CVE-2024-42161


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