Re: [PATCH 04/22] fsnotify: Remove fsnotify_duplicate_mark()

There are only two calls sites of fsnotify_duplicate_mark(). Those are in kernel/audit_tree.c and both are bogus. Vfsmount pointer is unused for audit tree, inode pointer and group gets set in fsnotify_add_mark_locked() later anyway, mask and free_mark are already set in alloc_chunk(). In fact, calling fsnotify_duplicate_mark() is actively harmful because following fsnotify_add_mark_locked() will leak group reference by overwriting the group pointer. So just remove the two calls to fsnotify_duplicate_mark() and the function. Signed-off-by: Jan Kara <jack(a)suse.cz&gt; --- fs/notify/mark.c | 12 ------------ include/linux/fsnotify_backend.h | 2 -- kernel/audit_tree.c | 6 ++---- 3 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/fs/notify/mark.c b/fs/notify/mark.c index d3fea0bd89e2..6043306e8e21 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -510,18 +510,6 @@ void fsnotify_detach_group_marks(struct fsnotify_group *group) } } -void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old) -{ - assert_spin_locked(&old->lock); - new->inode = old->inode; - new->mnt = old->mnt; - if (old->group) - fsnotify_get_group(old->group); - new->group = old->group; - new->mask = old->mask; - new->free_mark = old->free_mark; -} - /* * Nothing fancy, just initialize lists and locks and counters. */ diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 0cf34d6cc253..487246546ebe 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -323,8 +323,6 @@ extern void fsnotify_init_mark(struct fsnotify_mark *mark, void (*free_mark)(str extern struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group, struct inode *inode); /* find (and take a reference) to a mark associated with group and vfsmount */ extern struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group, struct vfsmount *mnt); -/* copy the values from old into new */ -extern void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old); /* set the ignored_mask of a mark */ extern void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mask); /* set the mask of a mark (might pin the object into memory */ diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index 8b1dde96a0fa..f3130eb0a4bd 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -258,8 +258,7 @@ static void untag_chunk(struct node *p) if (!new) goto Fallback; - fsnotify_duplicate_mark(&new->mark, entry); - if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.inode, NULL, 1)) { + if (fsnotify_add_mark(&new->mark, entry->group, entry->inode, NULL, 1)) { fsnotify_put_mark(&new->mark); goto Fallback; } @@ -395,8 +394,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree) return -ENOENT; } - fsnotify_duplicate_mark(chunk_entry, old_entry); - if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->inode, NULL, 1)) { + if (fsnotify_add_mark(chunk_entry, old_entry->group, old_entry->inode, NULL, 1)) { spin_unlock(&old_entry->lock); fsnotify_put_mark(chunk_entry); fsnotify_put_mark(old_entry); -- 2.10.2