[PATCH 6.1 043/236] bpf: Fix a verifier verbose message

Greg Kroah-Hartman
2024-05-14T11:29:28Z

From: Anton Protopopov <aspsk@isovalent.com>

[ Upstream commit 37eacb9f6e89fb399a79e952bc9c78eb3e16290e ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/bpf/verifier.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 27cc6e3db5a86..18b3f429abe17 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -13177,8 +13177,7 @@ 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);
}

--
2.43.0