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bpf: Add missing checks to avoid verbose verifier log

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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. Add missing checks.

Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114200542.912386-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Eduard Zingerman 2025-11-14 12:05:42 -08:00 • committed by Alexei Starovoitov
parent c1da3df719
commit e5d2e34e72
1 changed files with 6 additions and 4 deletions
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10
kernel/bpf/verifier.c
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@ -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;