CVE-2025-37807

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix kmemleak warning for percpu hashmap

Vlad Poenaru reported the following kmemleak issue:

unreferenced object 0x606fd7c44ac8 (size 32):

backtrace (crc 0):

pcpu_alloc_noprof+0x730/0xeb0

bpf_map_alloc_percpu+0x69/0xc0

prealloc_init+0x9d/0x1b0

htab_map_alloc+0x363/0x510

map_create+0x215/0x3a0

__sys_bpf+0x16b/0x3e0

__x64_sys_bpf+0x18/0x20

do_syscall_64+0x7b/0x150

entry_SYSCALL_64_after_hwframe+0x4b/0x53

Further investigation shows the reason is due to not 8-byte aligned

store of percpu pointer in htab_elem_set_ptr():

*(void __percpu **)(l->key + key_size) = pptr;

Note that the whole htab_elem alignment is 8 (for x86_64). If the key_size

is 4, that means pptr is stored in a location which is 4 byte aligned but

not 8 byte aligned. In mm/kmemleak.c, scan_block() scans the memory based

on 8 byte stride, so it won't detect above pptr, hence reporting the

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References