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In the Linux kernel, the following vulnerability has been...

High severity Unreviewed Published Jul 30, 2024 to the GitHub Advisory Database • Updated Aug 5, 2024

Package

No package listedSuggest a package

Affected versions

Unknown

Patched versions

Unknown

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.

References

Published by the National Vulnerability Database Jul 30, 2024
Published to the GitHub Advisory Database Jul 30, 2024
Last updated Aug 5, 2024

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS score

0.042%
(5th percentile)

Weaknesses

CVE ID

CVE-2024-42161

GHSA ID

GHSA-5hjg-m862-88fc

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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