diff options
Diffstat (limited to 'kernels/linux-libre-xen/net_handle_no_dst_on_skb_in_icmp6_send.patch')
| -rw-r--r-- | kernels/linux-libre-xen/net_handle_no_dst_on_skb_in_icmp6_send.patch | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/kernels/linux-libre-xen/net_handle_no_dst_on_skb_in_icmp6_send.patch b/kernels/linux-libre-xen/net_handle_no_dst_on_skb_in_icmp6_send.patch new file mode 100644 index 000000000..06448a90a --- /dev/null +++ b/kernels/linux-libre-xen/net_handle_no_dst_on_skb_in_icmp6_send.patch @@ -0,0 +1,68 @@ +From 79dc7e3f1cd323be4c81aa1a94faa1b3ed987fb2 Mon Sep 17 00:00:00 2001 +From: David Ahern <dsa@cumulusnetworks.com> +Date: Sun, 27 Nov 2016 18:52:53 -0800 +Subject: [PATCH] net: handle no dst on skb in icmp6_send + +Andrey reported the following while fuzzing the kernel with syzkaller: + +kasan: CONFIG_KASAN_INLINE enabled +kasan: GPF could be caused by NULL-ptr deref or user memory access +general protection fault: 0000 [#1] SMP KASAN +Modules linked in: +CPU: 0 PID: 3859 Comm: a.out Not tainted 4.9.0-rc6+ #429 +Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 +task: ffff8800666d4200 task.stack: ffff880067348000 +RIP: 0010:[<ffffffff833617ec>] [<ffffffff833617ec>] +icmp6_send+0x5fc/0x1e30 net/ipv6/icmp.c:451 +RSP: 0018:ffff88006734f2c0 EFLAGS: 00010206 +RAX: ffff8800666d4200 RBX: 0000000000000000 RCX: 0000000000000000 +RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000018 +RBP: ffff88006734f630 R08: ffff880064138418 R09: 0000000000000003 +R10: dffffc0000000000 R11: 0000000000000005 R12: 0000000000000000 +R13: ffffffff84e7e200 R14: ffff880064138484 R15: ffff8800641383c0 +FS: 00007fb3887a07c0(0000) GS:ffff88006cc00000(0000) knlGS:0000000000000000 +CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 +CR2: 0000000020000000 CR3: 000000006b040000 CR4: 00000000000006f0 +Stack: + ffff8800666d4200 ffff8800666d49f8 ffff8800666d4200 ffffffff84c02460 + ffff8800666d4a1a 1ffff1000ccdaa2f ffff88006734f498 0000000000000046 + ffff88006734f440 ffffffff832f4269 ffff880064ba7456 0000000000000000 +Call Trace: + [<ffffffff83364ddc>] icmpv6_param_prob+0x2c/0x40 net/ipv6/icmp.c:557 + [< inline >] ip6_tlvopt_unknown net/ipv6/exthdrs.c:88 + [<ffffffff83394405>] ip6_parse_tlv+0x555/0x670 net/ipv6/exthdrs.c:157 + [<ffffffff8339a759>] ipv6_parse_hopopts+0x199/0x460 net/ipv6/exthdrs.c:663 + [<ffffffff832ee773>] ipv6_rcv+0xfa3/0x1dc0 net/ipv6/ip6_input.c:191 + ... + +icmp6_send / icmpv6_send is invoked for both rx and tx paths. In both +cases the dst->dev should be preferred for determining the L3 domain +if the dst has been set on the skb. Fallback to the skb->dev if it has +not. This covers the case reported here where icmp6_send is invoked on +Rx before the route lookup. + +Fixes: 5d41ce29e ("net: icmp6_send should use dst dev to determine L3 domain") +Reported-by: Andrey Konovalov <andreyknvl@google.com> +Signed-off-by: David Ahern <dsa@cumulusnetworks.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + net/ipv6/icmp.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c +index 7370ad2..2772004 100644 +--- a/net/ipv6/icmp.c ++++ b/net/ipv6/icmp.c +@@ -447,8 +447,10 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, + + if (__ipv6_addr_needs_scope_id(addr_type)) + iif = skb->dev->ifindex; +- else +- iif = l3mdev_master_ifindex(skb_dst(skb)->dev); ++ else { ++ dst = skb_dst(skb); ++ iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev); ++ } + + /* + * Must not send error if the source does not uniquely |