* [PATCH net] ip: fix ip_mc_may_pull() return value
@ 2019-03-09 22:43 Eric Dumazet
2019-03-10 3:53 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Eric Dumazet @ 2019-03-09 22:43 UTC (permalink / raw)
To: David S . Miller
Cc: netdev, Eric Dumazet, Eric Dumazet, syzbot, Linus Lüssing
ip_mc_may_pull() must return 0 if there is a problem, not an errno.
syzbot reported :
BUG: KASAN: use-after-free in br_ip4_multicast_igmp3_report net/bridge/br_multicast.c:947 [inline]
BUG: KASAN: use-after-free in br_multicast_ipv4_rcv net/bridge/br_multicast.c:1631 [inline]
BUG: KASAN: use-after-free in br_multicast_rcv+0x3cd8/0x4440 net/bridge/br_multicast.c:1741
Read of size 4 at addr ffff88820a4084ee by task syz-executor.2/11183
CPU: 1 PID: 11183 Comm: syz-executor.2 Not tainted 5.0.0+ #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
__asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
br_ip4_multicast_igmp3_report net/bridge/br_multicast.c:947 [inline]
br_multicast_ipv4_rcv net/bridge/br_multicast.c:1631 [inline]
br_multicast_rcv+0x3cd8/0x4440 net/bridge/br_multicast.c:1741
br_handle_frame_finish+0xa3a/0x14c0 net/bridge/br_input.c:108
br_nf_hook_thresh+0x2ec/0x380 net/bridge/br_netfilter_hooks.c:1005
br_nf_pre_routing_finish+0x8e2/0x1750 net/bridge/br_netfilter_hooks.c:410
NF_HOOK include/linux/netfilter.h:289 [inline]
NF_HOOK include/linux/netfilter.h:283 [inline]
br_nf_pre_routing+0x7e7/0x13a0 net/bridge/br_netfilter_hooks.c:506
nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
nf_hook_slow+0xbf/0x1f0 net/netfilter/core.c:511
nf_hook include/linux/netfilter.h:244 [inline]
NF_HOOK include/linux/netfilter.h:287 [inline]
br_handle_frame+0x95b/0x1450 net/bridge/br_input.c:305
__netif_receive_skb_core+0xa96/0x3040 net/core/dev.c:4902
__netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:4971
__netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083
netif_receive_skb_internal+0x117/0x660 net/core/dev.c:5186
netif_receive_skb+0x6e/0x5a0 net/core/dev.c:5261
Fixes: ba5ea614622d ("bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Linus Lüssing <linus.luessing@c0d3.blue>
---
include/linux/igmp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/igmp.h b/include/linux/igmp.h
index cc85f4524dbfab28d03723c2fcb65c23730dee54..9c94b2ea789ceb9a06d9da0d8b07d28801732930 100644
--- a/include/linux/igmp.h
+++ b/include/linux/igmp.h
@@ -110,7 +110,7 @@ struct ip_mc_list {
static inline int ip_mc_may_pull(struct sk_buff *skb, unsigned int len)
{
if (skb_transport_offset(skb) + ip_transport_len(skb) < len)
- return -EINVAL;
+ return 0;
return pskb_may_pull(skb, len);
}
--
2.21.0.360.g471c308f928-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net] ip: fix ip_mc_may_pull() return value
2019-03-09 22:43 [PATCH net] ip: fix ip_mc_may_pull() return value Eric Dumazet
@ 2019-03-10 3:53 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2019-03-10 3:53 UTC (permalink / raw)
To: edumazet; +Cc: netdev, eric.dumazet, syzkaller, linus.luessing
From: Eric Dumazet <edumazet@google.com>
Date: Sat, 9 Mar 2019 14:43:38 -0800
> ip_mc_may_pull() must return 0 if there is a problem, not an errno.
>
> syzbot reported :
...
> Fixes: ba5ea614622d ("bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Cc: Linus Lüssing <linus.luessing@c0d3.blue>
Applied, thanks Eric.
^ permalink raw reply [flat|nested] 2+ messages in thread
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