* [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
@ 2021-09-23 4:05 Xin Long
2021-09-24 1:52 ` Marcelo Ricardo Leitner
2021-09-24 9:40 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Xin Long @ 2021-09-23 4:05 UTC (permalink / raw)
To: network dev, davem, kuba, linux-sctp; +Cc: Marcelo Ricardo Leitner
We should always check if skb_header_pointer's return is NULL before
using it, otherwise it may cause null-ptr-deref, as syzbot reported:
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline]
RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196
Call Trace:
<IRQ>
sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109
ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
dst_input include/net/dst.h:460 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize")
Reported-by: syzbot+581aff2ae6b860625116@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
net/sctp/input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 5ef86fdb1176..1f1786021d9c 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -702,7 +702,7 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
ch = skb_header_pointer(skb, offset, sizeof(*ch), &_ch);
/* Break out if chunk length is less then minimal. */
- if (ntohs(ch->length) < sizeof(_ch))
+ if (!ch || ntohs(ch->length) < sizeof(_ch))
break;
ch_end = offset + SCTP_PAD4(ntohs(ch->length));
--
2.27.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
2021-09-23 4:05 [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb Xin Long
@ 2021-09-24 1:52 ` Marcelo Ricardo Leitner
2021-09-24 9:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Marcelo Ricardo Leitner @ 2021-09-24 1:52 UTC (permalink / raw)
To: Xin Long; +Cc: network dev, davem, kuba, linux-sctp
On Thu, Sep 23, 2021 at 12:05:04AM -0400, Xin Long wrote:
> We should always check if skb_header_pointer's return is NULL before
> using it, otherwise it may cause null-ptr-deref, as syzbot reported:
>
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline]
> RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196
> Call Trace:
> <IRQ>
> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109
> ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
> ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
> NF_HOOK include/linux/netfilter.h:307 [inline]
> NF_HOOK include/linux/netfilter.h:301 [inline]
> ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
> dst_input include/net/dst.h:460 [inline]
> ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> NF_HOOK include/linux/netfilter.h:307 [inline]
> NF_HOOK include/linux/netfilter.h:301 [inline]
> ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
>
> Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize")
> Reported-by: syzbot+581aff2ae6b860625116@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
2021-09-23 4:05 [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb Xin Long
2021-09-24 1:52 ` Marcelo Ricardo Leitner
@ 2021-09-24 9:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-09-24 9:40 UTC (permalink / raw)
To: Xin Long; +Cc: netdev, davem, kuba, linux-sctp, marcelo.leitner
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Thu, 23 Sep 2021 00:05:04 -0400 you wrote:
> We should always check if skb_header_pointer's return is NULL before
> using it, otherwise it may cause null-ptr-deref, as syzbot reported:
>
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline]
> RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196
> Call Trace:
> <IRQ>
> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109
> ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
> ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
> NF_HOOK include/linux/netfilter.h:307 [inline]
> NF_HOOK include/linux/netfilter.h:301 [inline]
> ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
> dst_input include/net/dst.h:460 [inline]
> ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> NF_HOOK include/linux/netfilter.h:307 [inline]
> NF_HOOK include/linux/netfilter.h:301 [inline]
> ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
>
> [...]
Here is the summary with links:
- [net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
https://git.kernel.org/netdev/net/c/f7e745f8e944
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-09-23 4:05 [PATCH net] sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb Xin Long
2021-09-24 1:52 ` Marcelo Ricardo Leitner
2021-09-24 9:40 ` patchwork-bot+netdevbpf
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