syzbot


general protection fault in ip6_output

Status: fixed on 2024/06/05 19:57
Subsystems: net
[Documentation on labels]
Fix commit: 4db783d68b9b ipv6: prevent NULL dereference in ip6_output()
First crash: 72d, last: 53d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: unable to handle kernel paging request in ip6_output 1 32d 32d 0/3 upstream: reported on 2024/05/23 17:34

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 13431 Comm: syz-executor.3 Not tainted 6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:ip6_output+0x231/0x3f0 net/ipv6/ip6_output.c:237
Code: 3c 1e 00 49 89 df 74 08 4c 89 ef e8 d9 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 <42> 0f b6 04 38 84 c0 4c 8b 74 24 28 0f 85 61 01 00 00 8b 1b 31 ff
RSP: 0018:ffffc900037f6d58 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: ffff88806bfe0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8a1f628a R09: 1ffffffff1f51f45
R10: dffffc0000000000 R11: fffffbfff1f51f46 R12: ffff888079b01c80
R13: ffff88807d600000 R14: 1ffff1100f360392 R15: dffffc0000000000
FS:  00007f25eb09c6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 0000000021a22000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358
 sctp_v6_xmit+0x9f2/0x13f0 net/sctp/ipv6.c:248
 sctp_packet_transmit+0x26ad/0x2ca0 net/sctp/output.c:653
 sctp_packet_singleton+0x22c/0x320 net/sctp/outqueue.c:783
 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
 sctp_outq_flush+0x6d5/0x3e20 net/sctp/outqueue.c:1212
 sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
 sctp_do_sm+0x59cc/0x60c0 net/sctp/sm_sideeffect.c:1169
 sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73
 sctp_sendmsg_to_asoc+0xfa5/0x1800 net/sctp/socket.c:1841
 sctp_sendmsg+0x1bc3/0x3520 net/sctp/socket.c:2031
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f25ea27dd29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f25eb09c0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f25ea3abf80 RCX: 00007f25ea27dd29
RDX: 0000000000000001 RSI: 0000000020001080 RDI: 0000000000000003
RBP: 00007f25ea2ca47e R08: 0000000020000000 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f25ea3abf80 R15: 00007f25ea4cfa98
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ip6_output+0x231/0x3f0 net/ipv6/ip6_output.c:237
Code: 3c 1e 00 49 89 df 74 08 4c 89 ef e8 d9 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 <42> 0f b6 04 38 84 c0 4c 8b 74 24 28 0f 85 61 01 00 00 8b 1b 31 ff
RSP: 0018:ffffc900037f6d58 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: ffff88806bfe0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8a1f628a R09: 1ffffffff1f51f45
R10: dffffc0000000000 R11: fffffbfff1f51f46 R12: ffff888079b01c80
R13: ffff88807d600000 R14: 1ffff1100f360392 R15: dffffc0000000000
FS:  00007f25eb09c6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25ea2df328 CR3: 0000000021a22000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	3c 1e                	cmp    $0x1e,%al
   2:	00 49 89             	add    %cl,-0x77(%rcx)
   5:	df 74 08 4c          	fbstp  0x4c(%rax,%rcx,1)
   9:	89 ef                	mov    %ebp,%edi
   b:	e8 d9 58 db f7       	call   0xf7db58e9
  10:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
  15:	49 89 45 00          	mov    %rax,0x0(%r13)
  19:	49 89 c5             	mov    %rax,%r13
  1c:	48 8d 9d e0 05 00 00 	lea    0x5e0(%rbp),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	4c 8b 74 24 28       	mov    0x28(%rsp),%r14
  36:	0f 85 61 01 00 00    	jne    0x19d
  3c:	8b 1b                	mov    (%rbx),%ebx
  3e:	31 ff                	xor    %edi,%edi

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/03 03:38 upstream 49a73b1652c5 ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce general protection fault in ip6_output
2024/05/03 01:27 net 78cfe547607a ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in ip6_output
2024/04/27 02:09 net 6a30653b604a 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in ip6_output
2024/04/13 23:42 net f99c5f563c17 c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in ip6_output
* Struck through repros no longer work on HEAD.