mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-11-18 22:54:00 +00:00
92 lines
2.8 KiB
Diff
92 lines
2.8 KiB
Diff
From 0cce8f784e9e13abfe1d4b2af0c217bed9529fd0 Mon Sep 17 00:00:00 2001
|
|
From: Philip Pettersson <philip.pettersson@gmail.com>
|
|
Date: Wed, 30 Nov 2016 14:55:36 -0800
|
|
Subject: [PATCH 5/5] packet: fix race condition in packet_set_ring
|
|
|
|
When packet_set_ring creates a ring buffer it will initialize a
|
|
struct timer_list if the packet version is TPACKET_V3. This value
|
|
can then be raced by a different thread calling setsockopt to
|
|
set the version to TPACKET_V1 before packet_set_ring has finished.
|
|
|
|
This leads to a use-after-free on a function pointer in the
|
|
struct timer_list when the socket is closed as the previously
|
|
initialized timer will not be deleted.
|
|
|
|
The bug is fixed by taking lock_sock(sk) in packet_setsockopt when
|
|
changing the packet version while also taking the lock at the start
|
|
of packet_set_ring.
|
|
|
|
Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
|
|
Signed-off-by: Philip Pettersson <philip.pettersson@gmail.com>
|
|
Signed-off-by: Eric Dumazet <edumazet@google.com>
|
|
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
---
|
|
net/packet/af_packet.c | 18 ++++++++++++------
|
|
1 file changed, 12 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
|
|
index c434589..5ea0bff 100644
|
|
--- a/net/packet/af_packet.c
|
|
+++ b/net/packet/af_packet.c
|
|
@@ -3280,19 +3280,25 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
|
|
|
|
if (optlen != sizeof(val))
|
|
return -EINVAL;
|
|
- if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
|
|
- return -EBUSY;
|
|
if (copy_from_user(&val, optval, sizeof(val)))
|
|
return -EFAULT;
|
|
switch (val) {
|
|
case TPACKET_V1:
|
|
case TPACKET_V2:
|
|
case TPACKET_V3:
|
|
- po->tp_version = val;
|
|
- return 0;
|
|
+ break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
+ lock_sock(sk);
|
|
+ if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
|
|
+ ret = -EBUSY;
|
|
+ } else {
|
|
+ po->tp_version = val;
|
|
+ ret = 0;
|
|
+ }
|
|
+ release_sock(sk);
|
|
+ return ret;
|
|
}
|
|
case PACKET_RESERVE:
|
|
{
|
|
@@ -3755,6 +3761,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
|
|
/* Added to avoid minimal code churn */
|
|
struct tpacket_req *req = &req_u->req;
|
|
|
|
+ lock_sock(sk);
|
|
/* Opening a Tx-ring is NOT supported in TPACKET_V3 */
|
|
if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
|
|
WARN(1, "Tx-ring is not supported.\n");
|
|
@@ -3832,7 +3839,6 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
|
|
goto out;
|
|
}
|
|
|
|
- lock_sock(sk);
|
|
|
|
/* Detach socket from network */
|
|
spin_lock(&po->bind_lock);
|
|
@@ -3881,11 +3887,11 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
|
|
if (!tx_ring)
|
|
prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
|
|
}
|
|
- release_sock(sk);
|
|
|
|
if (pg_vec)
|
|
free_pg_vec(pg_vec, order, req->tp_block_nr);
|
|
out:
|
|
+ release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
--
|
|
2.10.2
|
|
|