CVE-2021-47397: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.8% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: 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

Affected products

• Linux Linux Kernel: from 4.8, before 4.14.249 (fixed in 4.14.249); from 4.15, before 4.19.209 (fixed in 4.19.209); from 4.20, before 5.4.151 (fixed in 5.4.151); from 5.5, before 5.10.71 (fixed in 5.10.71); from 5.11, before 5.14.10 (fixed in 5.14.10); version 5.15 only

Published 2024-05-21. Last modified 2026-08-04.