[PATCH bpf-next v1] bpf: a few missing checks to avoid verbose verifier log

[PATCH bpf-next v1] bpf: a few missing checks to avoid verbose verifier log

[Eduard Zingerman]

There are a few places where log level is not checked before calling
"verbose()". This forces programs working only at
BPF_LOG_LEVEL_STATS (e.g. veristat) to allocate unnecessarily large
log buffers.

Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
---
 kernel/bpf/verifier.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1268fa075d4c..99d62d765b24 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10720,8 +10720,9 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 			return err;
 		}
 
-		verbose(env, "Func#%d ('%s') is global and assumed valid.\n",
-			subprog, sub_name);
+		if (env->log.level & BPF_LOG_LEVEL)
+			verbose(env, "Func#%d ('%s') is global and assumed valid.\n",
+				subprog, sub_name);
 		if (env->subprog_info[subprog].changes_pkt_data)
 			clear_all_pkt_pointers(env);
 		/* mark global subprog for verifying after main prog */
@@ -19470,7 +19471,7 @@ static int propagate_precision(struct bpf_verifier_env *env,
 			bt_set_frame_slot(&env->bt, fr, i);
 			first = false;
 		}
-		if (!first)
+		if (!first && (env->log.level & BPF_LOG_LEVEL2))
 			verbose(env, "\n");
 	}
 
@@ -23698,7 +23699,8 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog)
 		struct bpf_subprog_arg_info *arg;
 		struct bpf_reg_state *reg;
 
-		verbose(env, "Validating %s() func#%d...\n", sub_name, subprog);
+		if (env->log.level & BPF_LOG_LEVEL)
+			verbose(env, "Validating %s() func#%d...\n", sub_name, subprog);
 		ret = btf_prepare_func_args(env, subprog);
 		if (ret)
 			goto out;
-- 
2.51.1

Re: [PATCH bpf-next v1] bpf: a few missing checks to avoid verbose verifier log

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Fri, 14 Nov 2025 12:05:42 -0800 you wrote:
> There are a few places where log level is not checked before calling
> "verbose()". This forces programs working only at
> BPF_LOG_LEVEL_STATS (e.g. veristat) to allocate unnecessarily large
> log buffers.
> 
> Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> 
> [...]

Here is the summary with links:
  - [bpf-next,v1] bpf: a few missing checks to avoid verbose verifier log
    https://git.kernel.org/bpf/bpf-next/c/e5d2e34e726b

You are awesome, thank you!
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