linux/arch/x86/net
Alexei Starovoitov 588a25e924 bpf: Fix extable address check.
The verifier checks that PTR_TO_BTF_ID pointer is either valid or NULL,
but it cannot distinguish IS_ERR pointer from valid one.

When offset is added to IS_ERR pointer it may become small positive
value which is a user address that is not handled by extable logic
and has to be checked for at the runtime.

Tighten BPF_PROBE_MEM pointer check code to prevent this case.

Fixes: 4c5de12759 ("bpf: Emit explicit NULL pointer checks for PROBE_LDX instructions.")
Reported-by: Lorenzo Fontana <lorenzo.fontana@elastic.co>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-12-16 21:41:04 +01:00
..
bpf_jit_comp32.c bpf,x86: Respect X86_FEATURE_RETPOLINE* 2021-10-28 23:25:29 +02:00
bpf_jit_comp.c bpf: Fix extable address check. 2021-12-16 21:41:04 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00