From: Ronnie Sahlberg <lsahlber@redhat.com>
To: linux-cifs <linux-cifs@vger.kernel.org>
Cc: Ronnie Sahlberg <lsahlber@redhat.com>
Subject: [PATCH] cifs: fix race between compound_send_recv() and the demultiplex thread
Date: Thu, 14 Nov 2019 11:42:26 +1000 [thread overview]
Message-ID: <20191114014226.26461-2-lsahlber@redhat.com> (raw)
In-Reply-To: <20191114014226.26461-1-lsahlber@redhat.com>
There is a race where the open() may be interrupted between when we receive the reply
but before we have invoked the callback in which case we never end up calling
handle_cancelled_mid() and thus leak an open handle on the server.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
fs/cifs/connect.c | 1 -
fs/cifs/transport.c | 3 ++-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index ccaa8bad336f..802604a7e692 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1223,7 +1223,6 @@ cifs_demultiplex_thread(void *p)
if (mids[i] != NULL) {
mids[i]->resp_buf_size = server->pdu_size;
if ((mids[i]->mid_flags & MID_WAIT_CANCELLED) &&
- mids[i]->mid_state == MID_RESPONSE_RECEIVED &&
server->ops->handle_cancelled_mid)
server->ops->handle_cancelled_mid(
mids[i]->resp_buf,
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index ca3de62688d6..28018a7eccb2 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -1119,7 +1119,8 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
midQ[i]->mid, le16_to_cpu(midQ[i]->command));
send_cancel(server, &rqst[i], midQ[i]);
spin_lock(&GlobalMid_Lock);
- if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
+ if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED ||
+ midQ[i]->mid_state == MID_RESPONSE_RECEIVED) {
midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
midQ[i]->callback = cifs_cancelled_callback;
cancelled_mid[i] = true;
--
2.13.6
next prev parent reply other threads:[~2019-11-14 1:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 1:42 [PATCH 0/1] cifs: fix race between compound_send_recv() and the demultiplex thread Ronnie Sahlberg
2019-11-14 1:42 ` Ronnie Sahlberg [this message]
2019-11-14 6:16 [PATCH 0/1] cifs: fix race between compound_send_recv() and the Ronnie Sahlberg
2019-11-14 6:16 ` [PATCH] cifs: fix race between compound_send_recv() and the demultiplex thread Ronnie Sahlberg
2019-11-15 18:07 ` Pavel Shilovsky
2019-11-20 23:57 ` Pavel Shilovsky
2019-11-21 0:09 ` Steve French
2019-11-21 19:34 ` Pavel Shilovsky
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