From: Eric Dumazet edumazet@google.com
[ Upstream commit 301bd140ed0b24f0da660874c7e8a47dad8c8222 ]
Rewrite tests in ip6erspan_tunnel_xmit() and erspan_fb_xmit() to not assume transport header is set.
syzbot reported:
WARNING: CPU: 0 PID: 1350 at include/linux/skbuff.h:2911 skb_transport_header include/linux/skbuff.h:2911 [inline] WARNING: CPU: 0 PID: 1350 at include/linux/skbuff.h:2911 ip6erspan_tunnel_xmit+0x15af/0x2eb0 net/ipv6/ip6_gre.c:963 Modules linked in: CPU: 0 PID: 1350 Comm: aoe_tx0 Not tainted 5.19.0-rc2-syzkaller-00160-g274295c6e53f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:skb_transport_header include/linux/skbuff.h:2911 [inline] RIP: 0010:ip6erspan_tunnel_xmit+0x15af/0x2eb0 net/ipv6/ip6_gre.c:963 Code: 0f 47 f0 40 88 b5 7f fe ff ff e8 8c 16 4b f9 89 de bf ff ff ff ff e8 a0 12 4b f9 66 83 fb ff 0f 85 1d f1 ff ff e8 71 16 4b f9 <0f> 0b e9 43 f0 ff ff e8 65 16 4b f9 48 8d 85 30 ff ff ff ba 60 00 RSP: 0018:ffffc90005daf910 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000000000ffff RCX: 0000000000000000 RDX: ffff88801f032100 RSI: ffffffff882e8d3f RDI: 0000000000000003 RBP: ffffc90005dafab8 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: ffff888024f21d40 R13: 000000000000a288 R14: 00000000000000b0 R15: ffff888025a2e000 FS: 0000000000000000(0000) GS:ffff88802c800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e425000 CR3: 000000006d099000 CR4: 0000000000152ef0 Call Trace: <TASK> __netdev_start_xmit include/linux/netdevice.h:4805 [inline] netdev_start_xmit include/linux/netdevice.h:4819 [inline] xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x188/0x880 net/core/dev.c:3604 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3815 [inline] __dev_queue_xmit+0x14a1/0x3900 net/core/dev.c:4219 dev_queue_xmit include/linux/netdevice.h:2994 [inline] tx+0x6a/0xc0 drivers/block/aoe/aoenet.c:63 kthread+0x1e7/0x3b0 drivers/block/aoe/aoecmd.c:1229 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 </TASK>
Fixes: d5db21a3e697 ("erspan: auto detect truncated ipv6 packets.") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: William Tu u9012063@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/ip_gre.c | 15 ++++++++++----- net/ipv6/ip6_gre.c | 15 ++++++++++----- 2 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index a7e32be8714f..6ab5c50aa7a8 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -519,7 +519,6 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) int tunnel_hlen; int version; int nhoff; - int thoff;
tun_info = skb_tunnel_info(skb); if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || @@ -553,10 +552,16 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev) (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) truncate = true;
- thoff = skb_transport_header(skb) - skb_mac_header(skb); - if (skb->protocol == htons(ETH_P_IPV6) && - (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) - truncate = true; + if (skb->protocol == htons(ETH_P_IPV6)) { + int thoff; + + if (skb_transport_header_was_set(skb)) + thoff = skb_transport_header(skb) - skb_mac_header(skb); + else + thoff = nhoff + sizeof(struct ipv6hdr); + if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) + truncate = true; + }
if (version == 1) { erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)), diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 3f88ba6555ab..9e0890738d93 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -944,7 +944,6 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb, __be16 proto; __u32 mtu; int nhoff; - int thoff;
if (!pskb_inet_may_pull(skb)) goto tx_err; @@ -965,10 +964,16 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb, (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) truncate = true;
- thoff = skb_transport_header(skb) - skb_mac_header(skb); - if (skb->protocol == htons(ETH_P_IPV6) && - (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)) - truncate = true; + if (skb->protocol == htons(ETH_P_IPV6)) { + int thoff; + + if (skb_transport_header_was_set(skb)) + thoff = skb_transport_header(skb) - skb_mac_header(skb); + else + thoff = nhoff + sizeof(struct ipv6hdr); + if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff) + truncate = true; + }
if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen)) goto tx_err;