[PATCH 5.15 017/244] cifs: Fix memory leak on the deferred close

Greg Kroah-Hartman
2022-08-23T09:37:59Z

From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>

commit ca08d0eac020d48a3141dbec0a3cf64fbdb17cde upstream.

xfstests on smb21 report kmemleak as below:

unreferenced object 0xffff8881767d6200 (size 64):
comm "xfs_io", pid 1284, jiffies 4294777434 (age 20.789s)
hex dump (first 32 bytes):
80 5a d0 11 81 88 ff ff 78 8a aa 63 81 88 ff ff .Z......x..c....
00 71 99 76 81 88 ff ff 00 00 00 00 00 00 00 00 .q.v............
backtrace:
[<00000000ad04e6ea>] cifs_close+0x92/0x2c0
[<0000000028b93c82>] __fput+0xff/0x3f0
[<00000000d8116851>] task_work_run+0x85/0xc0
[<0000000027e14f9e>] do_exit+0x5e5/0x1240
[<00000000fb492b95>] do_group_exit+0x58/0xe0
[<00000000129a32d9>] __x64_sys_exit_group+0x28/0x30
[<00000000e3f7d8e9>] do_syscall_64+0x35/0x80
[<00000000102e8a0b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

When cancel the deferred close work, we should also cleanup the struct
cifs_deferred_close.

Fixes: 9e992755be8f2 ("cifs: Call close synchronously during unlink/rename/lease break.")
Fixes: e3fc065682ebb ("cifs: Deferred close performance improvements")
Cc: stable@vger.kernel.org
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/cifs/misc.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -736,6 +736,8 @@ cifs_close_deferred_file(struct cifsInod
list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
if (delayed_work_pending(&cfile->deferred)) {
if (cancel_delayed_work(&cfile->deferred)) {
+ cifs_del_deferred_close(cfile);
+
tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
if (tmp_list == NULL)
break;
@@ -767,6 +769,8 @@ cifs_close_all_deferred_files(struct cif
cfile = list_entry(tmp, struct cifsFileInfo, tlist);
if (delayed_work_pending(&cfile->deferred)) {
if (cancel_delayed_work(&cfile->deferred)) {
+ cifs_del_deferred_close(cfile);
+
tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
if (tmp_list == NULL)
break;
@@ -802,6 +806,8 @@ cifs_close_deferred_file_under_dentry(st
if (strstr(full_path, path)) {
if (delayed_work_pending(&cfile->deferred)) {
if (cancel_delayed_work(&cfile->deferred)) {
+ cifs_del_deferred_close(cfile);
+
tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
if (tmp_list == NULL)
break;