CVE-2026-98588
CVE-2026-98588CVE-2026-98588
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc
sock_map_alloc() only rejects max_entries == 0 and otherwise allows any
u32 value. sock_map_free() then walks the sks[] array with a signed int
iterator:
int i;
for (i = 0; i < stab->map.max_entries; i++)
struct sock **psk = &stab->sks[i];
When a SOCKMAP is created with max_entries = 0xffffffff (UINT_MAX), the
allocation of 32 GiB can succeed on large-memory hosts. During free the
counter reaches 0x80000000, wraps to INT_MIN, is sign-extended by movslq
and turned into a ~16 GiB negative offset from stab->sks, pointing far
below the allocation.
The faulting access is an xchg() write in sock_map_free(). Without
KASAN, the same out-of-bounds write can fault on an unmapped vmalloc page
or corrupt an unrelated allocation if that vmalloc address is populated.
On a KASAN kernel with CONFIG_KASAN_VMALLOC=y, the shadow check for that
address hits an unmapp
Scoring
| Last modified | 2026-10-18 |