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>
This commit is contained in:
Dave Kleikamp
2009-08-31 11:07:12 -04:00
committed by Steve French
parent 1b49c55661
commit 6ab409b53d
5 changed files with 31 additions and 39 deletions

View File

@@ -800,7 +800,7 @@ set_via_filehandle:
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 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
__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 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
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,