[PATCH] ext4: add missing error check in __ext4_new_inode()

[Theodore Ts'o <tytso@mit.edu>]

It's possible for ext4_get_acl() to return an ERR_PTR.  So we need to
add a check for this case in __ext4_new_inode().  Otherwise on an
error we can end up oops the kernel.

This was getting triggered by xfstests generic/388, which is a test
which exercises the shutdown code path.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 fs/ext4/ialloc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index b4267d72f249..b32cf263750d 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -816,6 +816,8 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 		struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 
+		if (IS_ERR(p))
+			return ERR_CAST(p);
 		if (p) {
 			int acl_size = p->a_count * sizeof(ext4_acl_entry);
 
-- 
2.11.0.rc0.7.gbe5a750