CIFS: Fix a possible memory corruption during reconnect
commit 53e0e11efe9289535b060a51d4cf37c25e0d0f2b upstream.
We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index ced0e42..cd8025a 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -206,6 +206,9 @@
struct tcon_link *tlink,
struct cifs_pending_open *open);
extern void cifs_del_pending_open(struct cifs_pending_open *open);
+extern void cifs_put_tcp_session(struct TCP_Server_Info *server,
+ int from_reconnect);
+extern void cifs_put_tcon(struct cifs_tcon *tcon);
#if IS_ENABLED(CONFIG_CIFS_DFS_UPCALL)
extern void cifs_dfs_release_automount_timer(void);