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[192.26.29.3]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49240084928sm98858315e9.15.2026.06.19.13.59.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2026 13:59:51 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Eduard Zingerman , Emil Tsalapatis , kkd@meta.com, kernel-team@meta.com Subject: [PATCH bpf-next v2 16/17] bpf: Report Verifier Internal errors Date: Fri, 19 Jun 2026 22:59:29 +0200 Message-ID: <20260619205934.1312876-17-memxor@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260619205934.1312876-1-memxor@gmail.com> References: <20260619205934.1312876-1-memxor@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3841; i=memxor@gmail.com; h=from:subject; bh=q9ajVw+UbT9R4AfuVqKibwyGBOC515FvlOWhE+ZejB8=; b=owGbwMvMwCXmrmtenRyi38x4Wi2JIct0FVNVj+O5l6WmT4xanzUKdbfmJsyO5RDoPfvngUv5q Vi2ht6OUhYGMS4GWTFFlpL/+5iMT1T+DrRdxg0zh5UJZAgDF6cATKS9jpFhqph2/yqmy4X3uaOX zvq32Zz36i/lyu1/7RUfHv+h7FJyhOF/tp5xkHScmsGalzalqtfEvl5f9UScI1i9XrdVcPe9m// 4AQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=B34BD741DE8494B76E2F717880EF20021D46C59B Content-Transfer-Encoding: 8bit Augment selected existing internal-error paths with Verifier Internal Error reports. These reports avoid suggesting source-level fixes and instead identify the verifier invariant that failed. Cover non-overwritten BPF_PTR_POISON helper argument types and inconsistent kfunc graph-node argument classification. Signed-off-by: Kumar Kartikeya Dwivedi --- kernel/bpf/diagnostics.c | 16 ++++++++++++++++ kernel/bpf/diagnostics.h | 3 +++ kernel/bpf/verifier.c | 12 +++++++++++- 3 files changed, 30 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/diagnostics.c b/kernel/bpf/diagnostics.c index 18217f5f709a..d27bd314d194 100644 --- a/kernel/bpf/diagnostics.c +++ b/kernel/bpf/diagnostics.c @@ -1195,6 +1195,22 @@ void bpf_diag_report_limit(struct bpf_verifier_env *env, u32 insn_idx, bpf_diag_report_suggestion(env, "%s", suggestion); } +void bpf_diag_report_internal_error(struct bpf_verifier_env *env, + u32 insn_idx, const char *problem, + const char *reason) +{ + bpf_diag_report_header(env, BPF_DIAG_CATEGORY_VERIFIER_INTERNAL_ERROR, + problem); + bpf_diag_report_reason(env, "The verifier hit an internal error: %s", + reason); + + bpf_diag_report_section(env, "At"); + bpf_diag_report_source(env, insn_idx, "error", "%s", problem); + + bpf_diag_report_suggestion(env, + "Report this problem to bpf@vger.kernel.org with the full verifier log and program."); +} + void bpf_diag_report_invalid_deref(struct bpf_verifier_env *env, u32 insn_idx, int regno, const char *reg_name, const char *type_name, diff --git a/kernel/bpf/diagnostics.h b/kernel/bpf/diagnostics.h index 559c0169062c..97cdaad7b606 100644 --- a/kernel/bpf/diagnostics.h +++ b/kernel/bpf/diagnostics.h @@ -228,6 +228,9 @@ void bpf_diag_report_limit(struct bpf_verifier_env *env, u32 insn_idx, const char *limit, const char *suggestion, const char *reason_fmt, ...) __printf(5, 6); +void bpf_diag_report_internal_error(struct bpf_verifier_env *env, + u32 insn_idx, const char *problem, + const char *reason); void bpf_diag_record_branch(struct bpf_verifier_env *env, u32 insn_idx, bool cond_true); void bpf_diag_record_reg_mod(struct bpf_verifier_env *env, u32 insn_idx, diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ec51e0c81053..5c60fe033271 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -8481,6 +8481,9 @@ static int check_reg_type(struct bpf_verifier_env *env, struct bpf_reg_state *re verbose(env, "verifier internal error:"); verbose(env, "%s has non-overwritten BPF_PTR_POISON type\n", reg_arg_name(env, argno)); + bpf_diag_report_internal_error(env, env->insn_idx, + "poisoned helper argument type", + "helper type checking reached a non-overwritten BPF_PTR_POISON expected type."); return -EACCES; } @@ -12560,12 +12563,19 @@ static bool check_kfunc_is_graph_node_api(struct bpf_verifier_env *env, default: verbose(env, "verifier internal error: unexpected graph node argument type %s\n", btf_field_type_name(node_field_type)); + bpf_diag_report_internal_error(env, env->insn_idx, + "unexpected graph node argument type", + "the kfunc graph-node checker saw an unsupported graph node field type."); return false; } - if (!ret) + if (!ret) { verbose(env, "verifier internal error: %s node arg for unknown kfunc\n", btf_field_type_name(node_field_type)); + bpf_diag_report_internal_error(env, env->insn_idx, + "graph node argument for unknown kfunc", + "the kfunc graph-node checker could not map this graph node argument to the called kfunc."); + } return ret; } -- 2.53.0