bpf: Adjust BTF log size limit.

[ Upstream commit c5a2d43e998a821701029f23e25b62f9188e93ff ]

Make BTF log size limit to be the same as the verifier log size limit.
Otherwise tools that progressively increase log size and use the same log
for BTF loading and program loading will be hitting hard to debug EINVAL.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-7-alexei.starovoitov@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index aaf2fba..72534a6 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4135,7 +4135,7 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
                log->len_total = log_size;
 
                /* log attributes have to be sane */
-               if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
+               if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 ||
                    !log->level || !log->ubuf) {
                        err = -EINVAL;
                        goto errout;