bpf: Fix a crash when btf_parse_base() returns an error pointer

The pointer returned by btf_parse_base could be an error pointer.
IS_ERR() check is needed before calling btf_free(base_btf).

Fixes: 8646db238997 ("libbpf,bpf: Share BTF relocate-related code with kernel")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240830012214.1646005-1-martin.lau@linux.dev

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 520f49f422fee232f728029e185b258183ac7c51..e3377dd61f7ecdba922883c294217e6dd1ef3017 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6283,7 +6283,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
 
 errout:
        btf_verifier_env_free(env);
-       if (base_btf != vmlinux_btf)
+       if (!IS_ERR(base_btf) && base_btf != vmlinux_btf)
                btf_free(base_btf);
        if (btf) {
                kvfree(btf->data);