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| author | Eric Dumazet <edumazet@google.com> | 2018-03-26 18:08:07 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-27 17:53:27 +0300 |
| commit | 1dfe82ebd7d8fd43dba9948fdfb31f145014baa0 (patch) | |
| tree | 4fe585ba8a96b391b66b3616d400d46c8f5ce590 | |
| parent | d4c4bc11353f3bea6754f7d21e3612c9f32d1d64 (diff) | |
| download | linux-1dfe82ebd7d8fd43dba9948fdfb31f145014baa0.tar.xz | |
net: fix possible out-of-bound read in skb_network_protocol()
skb mac header is not necessarily set at the time skb_network_protocol()
is called. Use skb->data instead.
BUG: KASAN: slab-out-of-bounds in skb_network_protocol+0x46b/0x4b0 net/core/dev.c:2739
Read of size 2 at addr ffff8801b3097a0b by task syz-executor5/14242
CPU: 1 PID: 14242 Comm: syz-executor5 Not tainted 4.16.0-rc6+ #280
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_address_description+0x73/0x250 mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report+0x23c/0x360 mm/kasan/report.c:412
__asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:443
skb_network_protocol+0x46b/0x4b0 net/core/dev.c:2739
harmonize_features net/core/dev.c:2924 [inline]
netif_skb_features+0x509/0x9b0 net/core/dev.c:3011
validate_xmit_skb+0x81/0xb00 net/core/dev.c:3084
validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3142
packet_direct_xmit+0x117/0x790 net/packet/af_packet.c:256
packet_snd net/packet/af_packet.c:2944 [inline]
packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2969
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:639
___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
__sys_sendmsg+0xe5/0x210 net/socket.c:2081
Fixes: 19acc327258a ("gso: Handle Trans-Ether-Bridging protocol in skb_network_protocol()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Reported-by: Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 12be20535714..ef0cc6ea5f8d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2735,7 +2735,7 @@ __be16 skb_network_protocol(struct sk_buff *skb, int *depth) if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr)))) return 0; - eth = (struct ethhdr *)skb_mac_header(skb); + eth = (struct ethhdr *)skb->data; type = eth->h_proto; } |