cifs: Replace wrtPending with a real reference count
Currently, cifs_close() tries to wait until all I/O is complete and then
frees the file private data. If I/O does not completely in a reasonable
amount of time it frees the structure anyway, leaving a potential use-
after-free situation.
This patch changes the wrtPending counter to a complete reference count and
lets the last user free the structure.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 82d8383..1f09c76 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -800,7 +800,7 @@
if (open_file == NULL)
CIFSSMBClose(xid, pTcon, netfid);
else
- atomic_dec(&open_file->wrtPending);
+ cifsFileInfo_put(open_file);
out:
return rc;
}
@@ -1635,7 +1635,7 @@
__u32 npid = open_file->pid;
rc = CIFSSMBSetFileSize(xid, pTcon, attrs->ia_size, nfid,
npid, false);
- atomic_dec(&open_file->wrtPending);
+ cifsFileInfo_put(open_file);
cFYI(1, ("SetFSize for attrs rc = %d", rc));
if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
unsigned int bytes_written;
@@ -1790,7 +1790,7 @@
u16 nfid = open_file->netfid;
u32 npid = open_file->pid;
rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args, nfid, npid);
- atomic_dec(&open_file->wrtPending);
+ cifsFileInfo_put(open_file);
} else {
rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, args,
cifs_sb->local_nls,