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bpf: Avoid warning on unexpected map for tail call 

Before handling the tail call in record_func_key(), we check that the
map is of the expected type and log a verifier error if it isn't. Such
an error however doesn't indicate anything wrong with the verifier. The
check for map<>func compatibility is done after record_func_key(), by
check_map_func_compatibility().

Therefore, this patch logs the error as a typical reject instead of a
verifier error.

Fixes: d2e4c1e6c2 ("bpf: Constant map key tracking for prog array pokes")
Fixes: 0df1a55afa ("bpf: Warn on internal verifier errors")
Reported-by: syzbot+efb099d5833bca355e51@syzkaller.appspotmail.com
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/1f395b74e73022e47e04a31735f258babf305420.1751578055.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
pull/1309/head
Paul Chaignon 2025-07-03 23:35:09 +02:00 committed by Alexei Starovoitov
parent 71b4a9959e
commit 032547272e
1 changed files with 2 additions and 2 deletions
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4
kernel/bpf/verifier.c
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@ -11082,8 +11082,8 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
if (func_id != BPF_FUNC_tail_call)
return 0;
if (!map || map->map_type != BPF_MAP_TYPE_PROG_ARRAY) {
verifier_bug(env, "expected array map for tail call");
return -EFAULT;
verbose(env, "expected prog array map for tail call");
return -EINVAL;
}
reg = &regs[BPF_REG_3];