Btrfs: deal with NULL acl sent to btrfs_set_acl
It is legal for btrfs_set_acl to be sent a NULL acl. This
makes sure we don't dereference it. A similar patch was sent by
Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 1898f85..fa44e92 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -112,12 +112,14 @@
switch (type) {
case ACL_TYPE_ACCESS:
mode = inode->i_mode;
- ret = posix_acl_equiv_mode(acl, &mode);
- if (ret < 0)
- return ret;
- ret = 0;
- inode->i_mode = mode;
name = POSIX_ACL_XATTR_ACCESS;
+ if (acl) {
+ ret = posix_acl_equiv_mode(acl, &mode);
+ if (ret < 0)
+ return ret;
+ inode->i_mode = mode;
+ }
+ ret = 0;
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode))