diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2023-05-16 11:04:09 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-05-16 22:34:50 -0700 |
| commit | cff36398bd4c7d322d424433db437f3c3391c491 (patch) | |
| tree | 6f55e8e563f8fd60529100561da0d0a8308a63e0 /kernel/bpf/log.c | |
| parent | 34e78bab67c5de43e685c63cd8c27e0cd3239897 (diff) | |
bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log
It's trivial for user to trigger "verifier log line truncated" warning,
as verifier has a fixed-sized buffer of 1024 bytes (as of now), and there are at
least two pieces of user-provided information that can be output through
this buffer, and both can be arbitrarily sized by user:
- BTF names;
- BTF.ext source code lines strings.
Verifier log buffer should be properly sized for typical verifier state
output. But it's sort-of expected that this buffer won't be long enough
in some circumstances. So let's drop the check. In any case code will
work correctly, at worst truncating a part of a single line output.
Reported-by: syzbot+8b2a08dfbd25fd933d75@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230516180409.3549088-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/log.c')
| -rw-r--r-- | kernel/bpf/log.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index 046ddff37a76..850494423530 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -62,9 +62,6 @@ void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args); - WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1, - "verifier log line truncated - local buffer too short\n"); - if (log->level == BPF_LOG_KERNEL) { bool newline = n > 0 && log->kbuf[n - 1] == '\n'; |