In the Linux kernel, the following vulnerability has been resolved:
sctp: break out if skbheaderpointer returns NULL in sctprcvootb
We should always check if skbheaderpointer'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:sctprcvootb net/sctp/input.c:705 [inline] RIP: 0010:sctprcv+0x1d84/0x3220 net/sctp/input.c:196 Call Trace: <IRQ> sctp6rcv+0x38/0x60 net/sctp/ipv6.c:1109 ip6protocoldeliverrcu+0x2e9/0x1ca0 net/ipv6/ip6input.c:422 ip6inputfinish+0x62/0x170 net/ipv6/ip6input.c:463 NFHOOK include/linux/netfilter.h:307 [inline] NFHOOK include/linux/netfilter.h:301 [inline] ip6input+0x9c/0xd0 net/ipv6/ip6input.c:472 dstinput include/net/dst.h:460 [inline] ip6rcvfinish net/ipv6/ip6input.c:76 [inline] NFHOOK include/linux/netfilter.h:307 [inline] NFHOOK include/linux/netfilter.h:301 [inline] ipv6rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297