UBUNTU: SAUCE: (no-up) rds_ib_send() -- prevent local pings triggering BUG_ON()

Pining localhost on an infiniband connection can trigger a BUG_ON()
and cause a denial of service.

Fix identified by comparison of the RHEL source rpms.

CVE-2012-2372
BugLink: http://bugs.launchpad.net/bugs/1016299
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
index 84d90c97332f9178552f34f2e13973a351f6213a..4edcb1e47b084d29bb5fa4a08e31817bf75d9baa 100644 (file)
--- a/net/rds/ib_send.c
+++ b/net/rds/ib_send.c
@@ -501,7 +501,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
        int flow_controlled = 0;
        int nr_sig = 0;
 
-       BUG_ON(off % RDS_FRAG_SIZE);
+       BUG_ON(!conn->c_loopback && off % RDS_FRAG_SIZE);
        BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header));
 
        /* Do not send cong updates to IB loopback */