cifs: dereferencing first then checking
authorJeff Layton <jlayton@redhat.com>
Tue, 2 Nov 2010 20:22:50 +0000 (16:22 -0400)
committerSteve French <sfrench@us.ibm.com>
Thu, 4 Nov 2010 19:39:07 +0000 (19:39 +0000)
commitd38922949d377da7d47473c7868334408ae3b373
tree322cf984f274c45da08d57acc74d29bb5c5e5048
parent6ef933a38ade555a175ecab9d803e6bb73399763
cifs: dereferencing first then checking

This patch is based on Dan's original patch. His original description is
below:

Smatch complained about a couple checking for NULL after dereferencing
bugs.  I'm not super familiar with the code so I did the conservative
thing and move the dereferences after the checks.

The dereferences in cifs_lock() and cifs_fsync() were added in
ba00ba64cf0 "cifs: make various routines use the cifsFileInfo->tcon
pointer".  The dereference in find_writable_file() was added in
6508d904e6f "cifs: have find_readable/writable_file filter by fsuid".
The comments there say it's possible to trigger the NULL dereference
under stress.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
fs/cifs/file.c