[ 29/95] audit: dont free_chunk() after fsnotify_add_mark()

From: Ben Hutchings
Date: Sun Sep 09 2012 - 19:36:17 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszeredi@xxxxxxx>

commit 0fe33aae0e94b4097dd433c9399e16e17d638cd8 upstream.

Don't do free_chunk() after fsnotify_add_mark(). That one does a delayed unref
via the destroy list and this results in use-after-free.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Acked-by: Eric Paris <eparis@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
kernel/audit_tree.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 3a5ca58..69a5851 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -259,7 +259,7 @@ static void untag_chunk(struct node *p)

fsnotify_duplicate_mark(&new->mark, entry);
if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, NULL, 1)) {
- free_chunk(new);
+ fsnotify_put_mark(&new->mark);
goto Fallback;
}

@@ -322,7 +322,7 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree)

entry = &chunk->mark;
if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
- free_chunk(chunk);
+ fsnotify_put_mark(entry);
return -ENOSPC;
}

@@ -396,7 +396,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
fsnotify_duplicate_mark(chunk_entry, old_entry);
if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, NULL, 1)) {
spin_unlock(&old_entry->lock);
- free_chunk(chunk);
+ fsnotify_put_mark(chunk_entry);
fsnotify_put_mark(old_entry);
return -ENOSPC;
}


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