diff options
| author | David Ahern <dsa@cumulusnetworks.com> | 2017-03-06 08:53:04 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-22 12:04:16 +0100 |
| commit | e671f1cc588f380b17e1c0ce38c7c712d13dfe93 (patch) | |
| tree | bfc5b554751290f370ed8eb1eb33cc4ebc48e9fd | |
| parent | d0ebde92fbeb98eedbfce15cef3c86b652846d25 (diff) | |
vrf: Fix use-after-free in vrf_xmit
[ Upstream commit f7887d40e541f74402df0684a1463c0a0bb68c68 ]
KASAN detected a use-after-free:
[ 269.467067] BUG: KASAN: use-after-free in vrf_xmit+0x7f1/0x827 [vrf] at addr ffff8800350a21c0
[ 269.467067] Read of size 4 by task ssh/1879
[ 269.467067] CPU: 1 PID: 1879 Comm: ssh Not tainted 4.10.0+ #249
[ 269.467067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 269.467067] Call Trace:
[ 269.467067] dump_stack+0x81/0xb6
[ 269.467067] kasan_object_err+0x21/0x78
[ 269.467067] kasan_report+0x2f7/0x450
[ 269.467067] ? vrf_xmit+0x7f1/0x827 [vrf]
[ 269.467067] ? ip_output+0xa4/0xdb
[ 269.467067] __asan_load4+0x6b/0x6d
[ 269.467067] vrf_xmit+0x7f1/0x827 [vrf]
...
Which corresponds to the skb access after xmit handling. Fix by saving
skb->len and using the saved value to update stats.
Fixes: 193125dbd8eb2 ("net: Introduce VRF device driver")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/vrf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c index d6b619667f1a..349aecbc210a 100644 --- a/drivers/net/vrf.c +++ b/drivers/net/vrf.c @@ -345,6 +345,7 @@ static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) { + int len = skb->len; netdev_tx_t ret = is_ip_tx_frame(skb, dev); if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { @@ -352,7 +353,7 @@ static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) u64_stats_update_begin(&dstats->syncp); dstats->tx_pkts++; - dstats->tx_bytes += skb->len; + dstats->tx_bytes += len; u64_stats_update_end(&dstats->syncp); } else { this_cpu_inc(dev->dstats->tx_drps); |