From: Bharath SM <bharathsm@microsoft.com>
Date: Thu, 20 Apr 2023 13:54:33 +0000
Subject: [PATCH] SMB3: Add missing locks to protect deferred close file list
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: ab9ddc87a9055c4bebd6524d5d761d605d52e557

[ Upstream commit ab9ddc87a9055c4bebd6524d5d761d605d52e557 ]

cifs_del_deferred_close function has a critical section which modifies
the deferred close file list. We must acquire deferred_lock before
calling cifs_del_deferred_close function.

Fixes: ca08d0eac020 ("cifs: Fix memory leak on the deferred close")
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Acked-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/cifs/misc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 7f085ed2..f76e9bb7 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -749,7 +749,9 @@ cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
 	list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
 		if (delayed_work_pending(&cfile->deferred)) {
 			if (cancel_delayed_work(&cfile->deferred)) {
+				spin_lock(&cifs_inode->deferred_lock);
 				cifs_del_deferred_close(cfile);
+				spin_unlock(&cifs_inode->deferred_lock);
 
 				tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
 				if (tmp_list == NULL)
@@ -780,7 +782,9 @@ cifs_close_all_deferred_files(struct cifs_tcon *tcon)
 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
 		if (delayed_work_pending(&cfile->deferred)) {
 			if (cancel_delayed_work(&cfile->deferred)) {
+				spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
 				cifs_del_deferred_close(cfile);
+				spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
 
 				tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
 				if (tmp_list == NULL)
@@ -815,7 +819,9 @@ cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
 		if (strstr(full_path, path)) {
 			if (delayed_work_pending(&cfile->deferred)) {
 				if (cancel_delayed_work(&cfile->deferred)) {
+					spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
 					cifs_del_deferred_close(cfile);
+					spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
 
 					tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
 					if (tmp_list == NULL)
-- 
2.35.3