bpf: Fix NULL deref in map_kptr_match_type for scalar regs
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.1%
exploitation probability
0.1%top 98% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL deref in map_kptr_match_type for scalar regs
Commit ab6c637ad027 ("bpf: Fix a bpf_kptr_xchg() issue with local
kptr") refactored map_kptr_match_type() to branch on btf_is_kernel()
before checking base_type(). A scalar register stored into a kptr
slot has no btf, so the btf_is_kernel(reg->btf) call dereferences
NULL.
Move the base_type() != PTR_TO_BTF_ID guard before any reg->btf
access.
Affected products
Linux · LinuxReferences
https://git.kernel.org/stable/c/0a36c1f72888bca0237295a4da19cd91821a90behttps://git.kernel.org/stable/c/4d0a375887ab4d49e4da1ff10f9606cab8f7c3adhttps://git.kernel.org/stable/c/520454e839710c327808c2fcc98e28cee77355fchttps://git.kernel.org/stable/c/6982653ce5f119982aa58f1af58e7bfbebf39252https://git.kernel.org/stable/c/da1d615ce49a47986a8864e2371a26e97861085c