CVE Catalog

CVE-2024-57917

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

A race condition was discovered in the Linux kernel when printing the CPU map (cpumap). Modifying the CPU mask during the print operation causes a mismatch in formatted string length, leading to a warning and potential error in kvasprintf. The fix caches the cpumask into a temporary variable before printing.

Risk Assessment

The risk involves potential system disruption or information leakage about CPU configuration during hotplug operations, affecting stability and security in virtualized or cloud environments.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit that eliminates the race condition in cpumap printing). Monitor systems for instability related to CPU hotplug.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: topology: Keep the cpumask unchanged when printing cpumap During fuzz testing, the following warning was discovered: different return values (15 and 11) from vsnprintf("%*pbl ", ...) test:keyward is WARNING in kvasprintf WARNING: CPU: 55 PID: 1168477 at lib/kasprintf.c:30 kvasprintf+0x121/0x130 Call Trace: kvasprintf+0x121/0x130 kasprintf+0xa6/0xe0 bitmap_print_to_buf+0x89/0x100 core_siblings_list_read+0x7e/0xb0 kernfs_file_read_iter+0x15b/0x270 new_sync_read+0x153/0x260 vfs_read+0x215/0x290 ksys_read+0xb9/0x160 do_syscall_64+0x56/0x100 entry_SYSCALL_64_after_hwframe+0x78/0xe2 The call trace shows that kvasprintf() reported this warning during the printing of core_siblings_list. kvasprintf() has several steps: (1) First, calculate the length of the resulting formatted string. (2) Allocate a buffer based on the returned length. (3) Then, perform the actual string formatting. (4) Check whether the lengths of the formatted strings returned in steps (1) and (2) are consistent. If the core_cpumask is modified between steps (1) and (3), the lengths obtained in these two steps may not match. Indeed our test includes cpu hotplugging, which should modify core_cpumask while printing. To fix this issue, cache the cpumask into a temporary variable before calling cpumap_print_{list, cpumask}_to_buf(), to keep it unchanged during the printing process.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS