diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-03-07 10:07:16 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-03-08 10:14:15 +0000 |
| commit | b0ec2abf98267f14d032102551581c833b0659d3 (patch) | |
| tree | 9e77e3eaabb110e9332bf13ab0a4987e8907802f /net/ipv4/ip_tunnel.c | |
| parent | c4386ab4f6c600f75fdfd21143f89bac3e625d0d (diff) | |
net: ip_tunnel: make sure to pull inner header in ip_tunnel_rcv()
Apply the same fix than ones found in :
8d975c15c0cd ("ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()")
1ca1ba465e55 ("geneve: make sure to pull inner header in geneve_rx()")
We have to save skb->network_header in a temporary variable
in order to be able to recompute the network_header pointer
after a pskb_inet_may_pull() call.
pskb_inet_may_pull() makes sure the needed headers are in skb->head.
syzbot reported:
BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
BUG: KMSAN: uninit-value in IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline]
BUG: KMSAN: uninit-value in ip_tunnel_rcv+0xed9/0x2ed0 net/ipv4/ip_tunnel.c:409
__INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline]
ip_tunnel_rcv+0xed9/0x2ed0 net/ipv4/ip_tunnel.c:409
__ipgre_rcv+0x9bc/0xbc0 net/ipv4/ip_gre.c:389
ipgre_rcv net/ipv4/ip_gre.c:411 [inline]
gre_rcv+0x423/0x19f0 net/ipv4/ip_gre.c:447
gre_rcv+0x2a4/0x390 net/ipv4/gre_demux.c:163
ip_protocol_deliver_rcu+0x264/0x1300 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2b8/0x440 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:461 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
ip_rcv+0x46f/0x760 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5534 [inline]
__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5648
netif_receive_skb_internal net/core/dev.c:5734 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5793
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1556
tun_get_user+0x53b9/0x66e0 drivers/net/tun.c:2009
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2055
call_write_iter include/linux/fs.h:2087 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb6b/0x1520 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:652
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Uninit was created at:
__alloc_pages+0x9a6/0xe00 mm/page_alloc.c:4590
alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133
alloc_pages+0x1be/0x1e0 mm/mempolicy.c:2204
skb_page_frag_refill+0x2bf/0x7c0 net/core/sock.c:2909
tun_build_skb drivers/net/tun.c:1686 [inline]
tun_get_user+0xe0a/0x66e0 drivers/net/tun.c:1826
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2055
call_write_iter include/linux/fs.h:2087 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb6b/0x1520 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:652
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_tunnel.c')
| -rw-r--r-- | net/ipv4/ip_tunnel.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 1b6981de3f29..7af36e4f1647 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -378,7 +378,7 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, bool log_ecn_error) { const struct iphdr *iph = ip_hdr(skb); - int err; + int nh, err; #ifdef CONFIG_NET_IPGRE_BROADCAST if (ipv4_is_multicast(iph->daddr)) { @@ -404,8 +404,21 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, tunnel->i_seqno = ntohl(tpi->seq) + 1; } + /* Save offset of outer header relative to skb->head, + * because we are going to reset the network header to the inner header + * and might change skb->head. + */ + nh = skb_network_header(skb) - skb->head; + skb_set_network_header(skb, (tunnel->dev->type == ARPHRD_ETHER) ? ETH_HLEN : 0); + if (!pskb_inet_may_pull(skb)) { + DEV_STATS_INC(tunnel->dev, rx_length_errors); + DEV_STATS_INC(tunnel->dev, rx_errors); + goto drop; + } + iph = (struct iphdr *)(skb->head + nh); + err = IP_ECN_decapsulate(iph, skb); if (unlikely(err)) { if (log_ecn_error) |