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| author | Xin Long <lucien.xin@gmail.com> | 2021-09-23 07:05:04 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-24 12:36:19 +0300 |
| commit | f7e745f8e94492a8ac0b0a26e25f2b19d342918f (patch) | |
| tree | dfe1081ca45c521df61abab309e2a43527b61c6f | |
| parent | 9bc62afe03afdf33904f5e784e1ad68c50ff00bb (diff) | |
| download | linux-f7e745f8e94492a8ac0b0a26e25f2b19d342918f.tar.xz | |
sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sctp/input.c | 2 |
1 files changed, 1 insertions, 1 deletions
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)); |