3.6.11.1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Phil Sutter <phil.sutter@xxxxxxxxxxxx>
[ Upstream commit 9665d5d62487e8e7b1f546c00e11107155384b9a ]
When releasing a packet socket, the routine packet_set_ring() is reused
to free rings instead of allocating them. But when calling it for the
first time, it fills req->tp_block_nr with the value of rb->pg_vec_len
which in the second invocation makes it bail out since req->tp_block_nr
is greater zero but req->tp_block_size is zero.
This patch solves the problem by passing a zeroed auto-variable to
packet_set_ring() upon each invocation from packet_release().
As far as I can tell, this issue exists even since 69e3c75 (net: TX_RING
and packet mmap), i.e. the original inclusion of TX ring support into
af_packet, but applies only to sockets with both RX and TX ring
allocated, which is probably why this was unnoticed all the time.
Signed-off-by: Phil Sutter <phil.sutter@xxxxxxxxxxxx>
Cc: Johann Baudy <johann.baudy@xxxxxxxxxxx>
Cc: Daniel Borkmann <dborkman@xxxxxxxxxx>
Acked-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
net/packet/af_packet.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index c5c9e2a..70f7e18 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2443,13 +2443,15 @@ static int packet_release(struct socket *sock)
packet_flush_mclist(sk);
- memset(&req_u, 0, sizeof(req_u));
-
- if (po->rx_ring.pg_vec)
+ if (po->rx_ring.pg_vec) {
+ memset(&req_u, 0, sizeof(req_u));
packet_set_ring(sk, &req_u, 1, 0);
+ }
- if (po->tx_ring.pg_vec)
+ if (po->tx_ring.pg_vec) {
+ memset(&req_u, 0, sizeof(req_u));
packet_set_ring(sk, &req_u, 1, 1);
+ }
fanout_release(sk);
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html