// For flags

CVE-2024-42161

bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD

Severity Score

6.3
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

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.

Chenyuan Yang discovered that the CEC driver driver in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. Chenyuan Yang discovered that the USB Gadget subsystem in the Linux kernel did not properly check for the device to be enabled before writing. A local attacker could possibly use this to cause a denial of service.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Multiple
Confidentiality
Partial
Integrity
Complete
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-07-29 CVE Reserved
  • 2024-07-30 CVE Published
  • 2024-12-19 CVE Updated
  • 2025-03-18 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.10.222
Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.222"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.15.163
Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.163"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.1.98
Search vendor "Linux" for product "Linux Kernel" and version " < 6.1.98"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.6.39
Search vendor "Linux" for product "Linux Kernel" and version " < 6.6.39"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.9.9
Search vendor "Linux" for product "Linux Kernel" and version " < 6.9.9"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.10
Search vendor "Linux" for product "Linux Kernel" and version " < 6.10"
en
Affected