summary refs log tree commit diff
path: root/drivers/scsi/libiscsi_tcp.c
diff options
context:
space:
mode:
authorMike Christie <michaelc@cs.wisc.edu>2012-01-26 21:13:10 -0600
committerJames Bottomley <JBottomley@Parallels.com>2012-02-19 08:09:00 -0600
commit1304be5fe0efb42b7ec6a50dd8e1a9bce2adae17 (patch)
treebc3d95ab7c1cc5d779df4696aaa138b7cbd89825 /drivers/scsi/libiscsi_tcp.c
parentdf1c7baba1b7b3053950f3845a6575aca47ba9ce (diff)
downloadlinux-1304be5fe0efb42b7ec6a50dd8e1a9bce2adae17.tar.gz
[SCSI] libiscsi_tcp: fix max_r2t manipulation
Problem description from Xi Wang:
A large max_r2t could lead to integer overflow in subsequent call to
iscsi_tcp_r2tpool_alloc(), allocating a smaller buffer than expected
and leading to out-of-bounds write.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/libiscsi_tcp.c')
-rw-r--r--drivers/scsi/libiscsi_tcp.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 5715a3d0a3d3..c4996b081999 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -1170,6 +1170,24 @@ void iscsi_tcp_r2tpool_free(struct iscsi_session *session)
 }
 EXPORT_SYMBOL_GPL(iscsi_tcp_r2tpool_free);
 
+int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf)
+{
+	struct iscsi_session *session = conn->session;
+	unsigned short r2ts = 0;
+
+	sscanf(buf, "%hu", &r2ts);
+	if (session->max_r2t == r2ts)
+		return 0;
+
+	if (!r2ts || !is_power_of_2(r2ts))
+		return -EINVAL;
+
+	session->max_r2t = r2ts;
+	iscsi_tcp_r2tpool_free(session);
+	return iscsi_tcp_r2tpool_alloc(session);
+}
+EXPORT_SYMBOL_GPL(iscsi_tcp_set_max_r2t);
+
 void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 			      struct iscsi_stats *stats)
 {