CVE-2024-57917 topology: Keep the cpumask unchanged when printing cpumap

What is CVE-2024-57917?

CVE-2024-57917 is a high-severity vulnerability in Linux kernel, published on 19 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Which versions are affected by CVE-2024-57917?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-57917?

Apply the vendor's patch.

Is CVE-2024-57917 being exploited?

There is no known exploitation of CVE-2024-57917 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2024-57917, DEBIAN-CVE-2024-57917, GHSA-6w35-m3mc-pf7x, UBUNTU-CVE-2024-57917.