From b566f7a4f0e4f15f78f2e5fac273fa954991e03a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Thu, 2 Apr 2026 21:26:02 +0200 Subject: [PATCH] selftests/landlock: Fix snprintf truncation checks in audit helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit snprintf() returns the number of characters that would have been written, excluding the terminating NUL byte. When the output is truncated, this return value equals or exceeds the buffer size. Fix matches_log_domain_allocated() and matches_log_domain_deallocated() to detect truncation with ">=" instead of ">". Cc: Günther Noack Cc: stable@vger.kernel.org Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs") Reviewed-by: Günther Noack Link: https://lore.kernel.org/r/20260402192608.1458252-2-mic@digikod.net Signed-off-by: Mickaël Salaün --- tools/testing/selftests/landlock/audit.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/landlock/audit.h b/tools/testing/selftests/landlock/audit.h index 44eb433e9666..1049a0582af5 100644 --- a/tools/testing/selftests/landlock/audit.h +++ b/tools/testing/selftests/landlock/audit.h @@ -309,7 +309,7 @@ static int __maybe_unused matches_log_domain_allocated(int audit_fd, pid_t pid, log_match_len = snprintf(log_match, sizeof(log_match), log_template, pid); - if (log_match_len > sizeof(log_match)) + if (log_match_len >= sizeof(log_match)) return -E2BIG; return audit_match_record(audit_fd, AUDIT_LANDLOCK_DOMAIN, log_match, @@ -326,7 +326,7 @@ static int __maybe_unused matches_log_domain_deallocated( log_match_len = snprintf(log_match, sizeof(log_match), log_template, num_denials); - if (log_match_len > sizeof(log_match)) + if (log_match_len >= sizeof(log_match)) return -E2BIG; return audit_match_record(audit_fd, AUDIT_LANDLOCK_DOMAIN, log_match,