CVE-2024-36901

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ipv6: prevent NULL dereference in ip6_output()<br /> <br /> According to syzbot, there is a chance that ip6_dst_idev()<br /> returns NULL in ip6_output(). Most places in IPv6 stack<br /> deal with a NULL idev just fine, but not here.<br /> <br /> syzbot reported:<br /> <br /> general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI<br /> KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]<br /> CPU: 0 PID: 9775 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00157-g6a30653b604a #0<br /> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024<br /> RIP: 0010:ip6_output+0x231/0x3f0 net/ipv6/ip6_output.c:237<br /> Code: 3c 1e 00 49 89 df 74 08 4c 89 ef e8 19 58 db f7 48 8b 44 24 20 49 89 45 00 49 89 c5 48 8d 9d e0 05 00 00 48 89 d8 48 c1 e8 03 0f b6 04 38 84 c0 4c 8b 74 24 28 0f 85 61 01 00 00 8b 1b 31 ff<br /> RSP: 0018:ffffc9000927f0d8 EFLAGS: 00010202<br /> RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000040000<br /> RDX: ffffc900131f9000 RSI: 0000000000004f47 RDI: 0000000000004f48<br /> RBP: 0000000000000000 R08: ffffffff8a1f0b9a R09: 1ffffffff1f51fad<br /> R10: dffffc0000000000 R11: fffffbfff1f51fae R12: ffff8880293ec8c0<br /> R13: ffff88805d7fc000 R14: 1ffff1100527d91a R15: dffffc0000000000<br /> FS: 00007f135c6856c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 0000000020000080 CR3: 0000000064096000 CR4: 00000000003506f0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> NF_HOOK include/linux/netfilter.h:314 [inline]<br /> ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358<br /> sctp_v6_xmit+0x9f2/0x13f0 net/sctp/ipv6.c:248<br /> sctp_packet_transmit+0x26ad/0x2ca0 net/sctp/output.c:653<br /> sctp_packet_singleton+0x22c/0x320 net/sctp/outqueue.c:783<br /> sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]<br /> sctp_outq_flush+0x6d5/0x3e20 net/sctp/outqueue.c:1212<br /> sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]<br /> sctp_do_sm+0x59cc/0x60c0 net/sctp/sm_sideeffect.c:1169<br /> sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73<br /> __sctp_connect+0x9cd/0xe30 net/sctp/socket.c:1234<br /> sctp_connect net/sctp/socket.c:4819 [inline]<br /> sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834<br /> __sys_connect_file net/socket.c:2048 [inline]<br /> __sys_connect+0x2df/0x310 net/socket.c:2065<br /> __do_sys_connect net/socket.c:2075 [inline]<br /> __se_sys_connect net/socket.c:2072 [inline]<br /> __x64_sys_connect+0x7a/0x90 net/socket.c:2072<br /> do_syscall_x64 arch/x86/entry/common.c:52 [inline]<br /> do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f