[PATCH v5 bpf-next 2/5] landlock: Use path_walk_parent()
From: Song Liu <song@kernel.org>
Date: 2025-06-17 06:11:32
Also in:
bpf, linux-fsdevel, lkml
Subsystem:
landlock security module, security subsystem, the rest · Maintainers:
Mickaël Salaün, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
Use path_walk_parent() to walk a path up to its parent. No functional changes intended. Signed-off-by: Song Liu <song@kernel.org> --- security/landlock/fs.c | 30 ++++++++---------------------- 1 file changed, 8 insertions(+), 22 deletions(-)
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 6fee7c20f64d..e26ab8c34dd4 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c@@ -837,8 +837,8 @@ static bool is_access_to_paths_allowed( * restriction. */ while (true) { - struct dentry *parent_dentry; const struct landlock_rule *rule; + struct path root = {}; /* * If at least all accesses allowed on the destination are
@@ -895,34 +895,20 @@ static bool is_access_to_paths_allowed( /* Stops when a rule from each layer grants access. */ if (allowed_parent1 && allowed_parent2) break; -jump_up: - if (walker_path.dentry == walker_path.mnt->mnt_root) { - if (follow_up(&walker_path)) { - /* Ignores hidden mount points. */ - goto jump_up; - } else { - /* - * Stops at the real root. Denies access - * because not all layers have granted access. - */ - break; - } - } - if (unlikely(IS_ROOT(walker_path.dentry))) { + + if (unlikely(IS_ROOT(walker_path.dentry)) && + (walker_path.mnt->mnt_flags & MNT_INTERNAL)) { /* * Stops at disconnected root directories. Only allows * access to internal filesystems (e.g. nsfs, which is * reachable through /proc/<pid>/ns/<namespace>). */ - if (walker_path.mnt->mnt_flags & MNT_INTERNAL) { - allowed_parent1 = true; - allowed_parent2 = true; - } + allowed_parent1 = true; + allowed_parent2 = true; break; } - parent_dentry = dget_parent(walker_path.dentry); - dput(walker_path.dentry); - walker_path.dentry = parent_dentry; + if (path_walk_parent(&walker_path, &root)) + break; } path_put(&walker_path);
--
2.47.1