diff options
author | Willem de Bruijn <willemb@google.com> | 2018-12-31 01:24:36 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-09 19:38:31 +0300 |
commit | cde81154f86e36df0fad21c23976cc8b80c01600 (patch) | |
tree | 93ed3a27611ef4d7a6705425748153db05c81041 /net/ipv6/ip6mr.c | |
parent | 0d2b652b0732bcf1536394e9d1fb37223cf541a1 (diff) | |
download | linux-cde81154f86e36df0fad21c23976cc8b80c01600.tar.xz |
ip: validate header length on virtual device xmit
[ Upstream commit cb9f1b783850b14cbd7f87d061d784a666dfba1f ]
KMSAN detected read beyond end of buffer in vti and sit devices when
passing truncated packets with PF_PACKET. The issue affects additional
ip tunnel devices.
Extend commit 76c0ddd8c3a6 ("ip6_tunnel: be careful when accessing the
inner header") and commit ccfec9e5cb2d ("ip_tunnel: be careful when
accessing the inner header").
Move the check to a separate helper and call at the start of each
ndo_start_xmit function in net/ipv4 and net/ipv6.
Minor changes:
- convert dev_kfree_skb to kfree_skb on error path,
as dev_kfree_skb calls consume_skb which is not for error paths.
- use pskb_network_may_pull even though that is pedantic here,
as the same as pskb_may_pull for devices without llheaders.
- do not cache ipv6 hdrs if used only once
(unsafe across pskb_may_pull, was more relevant to earlier patch)
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv6/ip6mr.c')
-rw-r--r-- | net/ipv6/ip6mr.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index fb70bbd9e6d1..331e6b6dd252 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -51,6 +51,7 @@ #include <linux/export.h> #include <net/ip6_checksum.h> #include <linux/netconf.h> +#include <net/ip_tunnels.h> #include <linux/nospec.h> @@ -593,13 +594,12 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, .flowi6_iif = skb->skb_iif ? : LOOPBACK_IFINDEX, .flowi6_mark = skb->mark, }; - int err; - err = ip6mr_fib_lookup(net, &fl6, &mrt); - if (err < 0) { - kfree_skb(skb); - return err; - } + if (!pskb_inet_may_pull(skb)) + goto tx_err; + + if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0) + goto tx_err; read_lock(&mrt_lock); dev->stats.tx_bytes += skb->len; @@ -608,6 +608,11 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, read_unlock(&mrt_lock); kfree_skb(skb); return NETDEV_TX_OK; + +tx_err: + dev->stats.tx_errors++; + kfree_skb(skb); + return NETDEV_TX_OK; } static int reg_vif_get_iflink(const struct net_device *dev) |