From d3df7ed4683f8c1b35672a40bf20af6a08ef8ca9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 7 Sep 2026 12:36:08 +0200 Subject: [PATCH] landlock: Clean up ruleset validation checks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit landlock_merge_ruleset() checks for a NULL ruleset after dereferencing it in lockdep_assert_held(). Move the assertion after the check so the defensive path remains effective. The mask-validation comment originated in landlock_add_fs_access_mask() to explain that its WARN_ON_ONCE() checked a caller invariant. It became self-referential when this helper and its network and scope counterparts were inlined into landlock_create_ruleset(). Restate the invariant without naming the caller. Keep both as defensive callee checks. Moving the assertion preserves the NULL check's ability to warn and return -EINVAL, while invalid masks remain warned about and masked. Reported-by: Günther Noack Closes: https://patch.msgid.link/aobYhIt3vcs2xN0b@google.com Closes: https://patch.msgid.link/aobasxUDQ8b7GYXl@google.com Reviewed-by: Günther Noack Link: https://patch.msgid.link/20260907103609.113325-1-mic@digikod.net Signed-off-by: Mickaël Salaün --- security/landlock/domain.c | 3 ++- security/landlock/ruleset.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/security/landlock/domain.c b/security/landlock/domain.c index 93c7104fd6b2..4031b581be07 100644 --- a/security/landlock/domain.c +++ b/security/landlock/domain.c @@ -439,10 +439,11 @@ landlock_merge_ruleset(struct landlock_domain *const parent, int err; might_sleep(); - lockdep_assert_held(&ruleset->lock); if (WARN_ON_ONCE(!ruleset)) return ERR_PTR(-EINVAL); + lockdep_assert_held(&ruleset->lock); + if (parent) { if (parent->num_layers >= LANDLOCK_MAX_NUM_LAYERS) return ERR_PTR(-E2BIG); diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 0d07707523cd..a5d135d085cb 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -58,7 +58,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask, new_ruleset->id = landlock_get_id_range(1); #endif /* CONFIG_TRACEPOINTS */ - /* Should already be checked in landlock_create_ruleset(). */ + /* The caller must only pass supported access rights and scopes. */ if (fs_access_mask) { const access_mask_t mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS;