On 17/03/2022 02:26, Paul Moore wrote:
On Mon, Feb 21, 2022 at 4:15 PM Mickaël Salaün <mic@xxxxxxxxxxx> wrote:
From: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx>
Move the SB_NOUSER and IS_PRIVATE dentry check to a standalone
is_nouser_or_private() helper. This will be useful for a following
commit.
Move get_mode_access() and maybe_remove() to make them usable by new
code provided by a following commit.
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220221212522.320243-6-mic@xxxxxxxxxxx
---
security/landlock/fs.c | 87 ++++++++++++++++++++++--------------------
1 file changed, 46 insertions(+), 41 deletions(-)
One nit-picky comment below, otherwise it looks fine to me.
Reviewed-by: Paul Moore <paul@xxxxxxxxxxxxxx>
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 9662f9fb3cd0..3886f9ad1a60 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -257,6 +257,18 @@ static inline bool unmask_layers(const struct landlock_rule *const rule,
return false;
}
+static inline bool is_nouser_or_private(const struct dentry *dentry)
+{
+ /*
+ * Allows access to pseudo filesystems that will never be mountable
+ * (e.g. sockfs, pipefs), but can still be reachable through
+ * /proc/<pid>/fd/<file-descriptor> .
+ */
I might suggest moving this explanation up to a function header comment block.
Sounds good.
+ return (dentry->d_sb->s_flags & SB_NOUSER) ||
+ (d_is_positive(dentry) &&
+ unlikely(IS_PRIVATE(d_backing_inode(dentry))));
+}
+
static int check_access_path(const struct landlock_ruleset *const domain,
const struct path *const path,
const access_mask_t access_request)
--
paul-moore.com
