bpf: Fix a verifier verbose message

Long ago a map file descriptor in a pseudo ldimm64 instruction could
only be present as an immediate value insn[0].imm, and thus this value
was used in a verbose verifier message printed when the file descriptor
wasn't valid. Since addition of BPF_PSEUDO_MAP_IDX_VALUE/BPF_PSEUDO_MAP_IDX
the insn[0].imm field can also contain an index pointing to the file
descriptor in the attr.fd_array array. However, if the file descriptor
is invalid, the verifier still prints the verbose message containing
value of insn[0].imm. Patch the verifier message to always print the
actual file descriptor value.

Fixes: 387544bfa291 ("bpf: Introduce fd_idx")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240412141100.3562942-1-aspsk@isovalent.com

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 98188379d5c77d79d3a5e764659ed4426f931d14..aa24beb65393c8ed447a873d545bdccc3487833d 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -18289,8 +18289,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
                        f = fdget(fd);
                        map = __bpf_map_get(f);
                        if (IS_ERR(map)) {
-                               verbose(env, "fd %d is not pointing to valid bpf_map\n",
-                                       insn[0].imm);
+                               verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
                                return PTR_ERR(map);
                        }