staging/lustre/mdc: Handle empty but non-zero acl xattr
authorChristopher J. Morrone <morrone2@llnl.gov>
Thu, 26 Mar 2015 01:53:18 +0000 (21:53 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Mar 2015 10:10:24 +0000 (11:10 +0100)
commitf42894004727ffdfb3b0826b0047eaf44cbdece6
tree0b609f312ce92297a35888641c0fa81aece71959
parentc61ac9791e357e0589f688a0a5ee4ad24f41cd84
staging/lustre/mdc: Handle empty but non-zero acl xattr

We have found that posix_acl_access can have a value
of \002\000\000\000.  In that case body->aclsize is
non-zero, but the there are no actuall acls stored
in the xattr.

In mdc_unpack_acl(), it only checks IS_ERR() on the
pointer returned by posix_acl_from_xattr(), it does not
check for NULL.  Because of the above situation, the
xattr aclsize can be non-zero, but posic_acl_from_xattr()
still returns NULL.  Passing NULL to posix_acl_valid()
crashes the kernel.

We add a check to properly handle the NULL return value.

Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/11989
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5150
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/lustre/lustre/mdc/mdc_request.c