ocfs2: fix null pointer dereference in ocfs2_dir_foreach_blk_id()

pibroch · torvalds · commit d6394b590029 · 2013-08-13T17:57:49.000-07:00
Fix a NULL pointer deference while removing an empty directory, which was introduced by commit 3704412 ("[readdir] convert ocfs2"). BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<(null)>] (null) PGD 6da85067 PUD 6da89067 PMD 0 Oops: 0010 [#1] SMP CPU: 0 PID: 6564 Comm: rmdir Tainted: G O 3.11.0-rc1 #4 RIP: 0010:[<0000000000000000>] [< (null)>] (null) Call Trace: ocfs2_dir_foreach+0x49/0x50 [ocfs2] ocfs2_empty_dir+0x12c/0x3e0 [ocfs2] ocfs2_unlink+0x56e/0xc10 [ocfs2] vfs_rmdir+0xd5/0x140 do_rmdir+0x1cb/0x1e0 SyS_rmdir+0x16/0x20 system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff88006daddc10> CR2: 0000000000000000 [dan.carpenter@oracle.com: fix pointer math] Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reported-by: David Weber <wb@munzinger.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
@@ -2153,11 +2153,9 @@ int ocfs2_empty_dir(struct inode *inode)
 {
 	int ret;
 	struct ocfs2_empty_dir_priv priv = {
-		.ctx.actor = ocfs2_empty_dir_filldir
+		.ctx.actor = ocfs2_empty_dir_filldir,
 	};
 
-	memset(&priv, 0, sizeof(priv));
-
 	if (ocfs2_dir_indexed(inode)) {
 		ret = ocfs2_empty_dir_dx(inode, &priv);
 		if (ret)
