RH Bugzilla: 1702264
We need to protect so that the call to smb2_reconnect() in
smb2_reconnect_server() does not end up freeing the session
because it can lead to a use after free and crash.
Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
---
fs/cifs/smb2pdu.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 565b60b62f4d..ab8dc73d2282 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3113,9 +3113,14 @@ void smb2_reconnect_server(struct work_struct *work)
tcon_exist = true;
}
}
+ /*
+ * IPC has the same lifetime as its session and uses its
+ * refcount.
+ */
if (ses->tcon_ipc && ses->tcon_ipc->need_reconnect) {
list_add_tail(&ses->tcon_ipc->rlist, &tmp_list);
tcon_exist = true;
+ ses->ses_count++;
}
}
/*
@@ -3134,7 +3139,10 @@ void smb2_reconnect_server(struct work_struct *work)
else
resched = true;
list_del_init(&tcon->rlist);
- cifs_put_tcon(tcon);
+ if (tcon->ipc)
+ cifs_put_smb_ses(tcon->ses);
+ else
+ cifs_put_tcon(tcon);
}
cifs_dbg(FYI, "Reconnecting tcons finished\n");
--
2.13.6
