diff options
Diffstat (limited to 'fs/cifs/misc.c')
| -rw-r--r-- | fs/cifs/misc.c | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 524dbdfb7184..184138b4eb8c 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -1,22 +1,10 @@ +// SPDX-License-Identifier: LGPL-2.1 /* * fs/cifs/misc.c * * Copyright (C) International Business Machines Corp., 2002,2008 * Author(s): Steve French (sfrench@us.ibm.com) * - * This library is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as published - * by the Free Software Foundation; either version 2.1 of the License, or - * (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See - * the GNU Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this library; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/slab.h> @@ -672,6 +660,11 @@ cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); } +/* + * Critical section which runs after acquiring deferred_lock. + * As there is no reference count on cifs_deferred_close, pdclose + * should not be used outside deferred_lock. + */ bool cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) { @@ -688,6 +681,9 @@ cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close ** return false; } +/* + * Critical section which runs after acquiring deferred_lock. + */ void cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) { @@ -707,6 +703,9 @@ cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close * list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); } +/* + * Critical section which runs after acquiring deferred_lock. + */ void cifs_del_deferred_close(struct cifsFileInfo *cfile) { @@ -738,15 +737,19 @@ void cifs_close_all_deferred_files(struct cifs_tcon *tcon) { struct cifsFileInfo *cfile; - struct cifsInodeInfo *cinode; struct list_head *tmp; spin_lock(&tcon->open_file_lock); list_for_each(tmp, &tcon->openFileList) { cfile = list_entry(tmp, struct cifsFileInfo, tlist); - cinode = CIFS_I(d_inode(cfile->dentry)); - if (delayed_work_pending(&cfile->deferred)) - mod_delayed_work(deferredclose_wq, &cfile->deferred, 0); + if (delayed_work_pending(&cfile->deferred)) { + /* + * If there is no pending work, mod_delayed_work queues new work. + * So, Increase the ref count to avoid use-after-free. + */ + if (!mod_delayed_work(deferredclose_wq, &cfile->deferred, 0)) + cifsFileInfo_get(cfile); + } } spin_unlock(&tcon->open_file_lock); } |