audit: fix potential double free on error path from fsnotify_add_inode_mark

commit ad982c3be4e60c7d39c03f782733503cbd88fd2a upstream.

Audit_alloc_mark() assign pathname to audit_mark->path, on error path
from fsnotify_add_inode_mark(), fsnotify_put_mark will free memory
of audit_mark->path, but the caller of audit_alloc_mark will free
the pathname again, so there will be double free problem.

Fix this by resetting audit_mark->path to NULL pointer on error path
from fsnotify_add_inode_mark().

Cc: stable@vger.kernel.org
Fixes: 7b1293234084d ("fsnotify: Add group pointer in fsnotify_init_mark()")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index 60739d5..c428312 100644 (file)
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -102,6 +102,7 @@ struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pa
 
        ret = fsnotify_add_inode_mark(&audit_mark->mark, inode, true);
        if (ret < 0) {
+               audit_mark->path = NULL;
                fsnotify_put_mark(&audit_mark->mark);
                audit_mark = ERR_PTR(ret);
        }