CVE-2021-47397

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb<br /> <br /> We should always check if skb_header_pointer&amp;#39;s return is NULL before<br /> using it, otherwise it may cause null-ptr-deref, as syzbot reported:<br /> <br /> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]<br /> RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline]<br /> RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196<br /> Call Trace:<br /> <br /> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109<br /> ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422<br /> ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463<br /> NF_HOOK include/linux/netfilter.h:307 [inline]<br /> NF_HOOK include/linux/netfilter.h:301 [inline]<br /> ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472<br /> dst_input include/net/dst.h:460 [inline]<br /> ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]<br /> NF_HOOK include/linux/netfilter.h:307 [inline]<br /> NF_HOOK include/linux/netfilter.h:301 [inline]<br /> ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297