[PATCH 3.12 075/182] iscsi-target: Fix ERL=2 ASYNC_EVENT connection pointer bug

Jiri Slaby
2014-05-13T09:58:22Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit d444edc679e7713412f243b792b1f964e5cff1e1 upstream.

This patch fixes a long-standing bug in iscsit_build_conn_drop_async_message()
where during ERL=2 connection recovery, a bogus conn_p pointer could
end up being used to send the ISCSI_OP_ASYNC_EVENT + DROPPING_CONNECTION
notifying the initiator that cmd->logout_cid has failed.

The bug was manifesting itself as an OOPs in iscsit_allocate_cmd() with
a bogus conn_p pointer in iscsit_build_conn_drop_async_message().

Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com>
Reported-by: santosh kulkarni <santosh.kulkarni@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/target/iscsi/iscsi_target.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index b5e574659785..b47c2be1c427 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -2476,6 +2476,7 @@ static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
{
struct iscsi_cmd *cmd;
struct iscsi_conn *conn_p;
+ bool found = false;

/*
* Only send a Asynchronous Message on connections whos network
@@ -2484,11 +2485,12 @@ static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
iscsit_inc_conn_usage_count(conn_p);
+ found = true;
break;
}
}

- if (!conn_p)
+ if (!found)
return;

cmd = iscsit_allocate_cmd(conn_p, GFP_ATOMIC);
--
1.9.3