syzbot


general protection fault in llc_conn_state_process (2)

Status: upstream: reported on 2025/01/29 06:03
Reported-by: syzbot+532e4c364578ed6fc223@syzkaller.appspotmail.com
First crash: 7d01h, last: 7d01h
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream UBSAN: array-index-out-of-bounds in llc_conn_state_process (2) net 13 1d23h 246d 0/28 upstream: reported on 2024/06/03 15:59
linux-6.1 general protection fault in llc_conn_state_process 1 160d 160d 0/3 auto-obsoleted due to no activity on 2024/12/06 20:07
upstream UBSAN: array-index-out-of-bounds in llc_conn_state_process net 2 1061d 1174d 0/28 auto-closed as invalid on 2022/07/10 02:25
linux-5.15 KASAN: global-out-of-bounds Read in llc_conn_state_process 1 370d 370d 0/3 auto-obsoleted due to no activity on 2024/05/10 14:15

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 1190 Comm: kworker/0:3 Not tainted 6.1.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: mld mld_ifc_work
RIP: 0010:llc_conn_state_process+0xab6/0x1230
Code: f6 0f 94 c0 4c 8b 75 00 8d 54 00 01 b8 01 00 00 00 bd 07 00 00 00 0f 44 e8 4c 89 f0 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df <42> 0f b6 04 20 84 c0 0f 85 82 06 00 00 41 89 16 42 0f b6 04 23 84
RSP: 0018:ffffc90000007b60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff1100f7fca02 RCX: ffff8880279c8000
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000007 R08: ffffffff88c11d4b R09: ffffffff88c11c93
R10: 0000000000000005 R11: ffff8880279c8000 R12: dffffc0000000000
R13: ffff88807bfe5000 R14: 0000000000000000 R15: ffff88807bfe5012
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd03ff8 CR3: 0000000028eec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 llc_process_tmr_ev net/llc/llc_c_ac.c:1445 [inline]
 llc_conn_tmr_common_cb+0x347/0x8a0 net/llc/llc_c_ac.c:1331
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 do_softirq+0x162/0x240 kernel/softirq.c:472
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:396
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:861 [inline]
 __dev_queue_xmit+0x173c/0x3d50 net/core/dev.c:4330
 dev_queue_xmit include/linux/netdevice.h:3043 [inline]
 neigh_hh_output include/net/neighbour.h:528 [inline]
 neigh_output include/net/neighbour.h:542 [inline]
 ip6_finish_output2+0xeae/0x15f0 net/ipv6/ip6_output.c:138
 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline]
 ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:216
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK+0x167/0x530 include/linux/netfilter.h:302
 mld_sendpack+0x85e/0xde0 net/ipv6/mcast.c:1820
 mld_send_cr net/ipv6/mcast.c:2121 [inline]
 mld_ifc_work+0x7d7/0xc90 net/ipv6/mcast.c:2653
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:llc_conn_state_process+0xab6/0x1230
Code: f6 0f 94 c0 4c 8b 75 00 8d 54 00 01 b8 01 00 00 00 bd 07 00 00 00 0f 44 e8 4c 89 f0 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df <42> 0f b6 04 20 84 c0 0f 85 82 06 00 00 41 89 16 42 0f b6 04 23 84
RSP: 0018:ffffc90000007b60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff1100f7fca02 RCX: ffff8880279c8000
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000007 R08: ffffffff88c11d4b R09: ffffffff88c11c93
R10: 0000000000000005 R11: ffff8880279c8000 R12: dffffc0000000000
R13: ffff88807bfe5000 R14: 0000000000000000 R15: ffff88807bfe5012
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd03ff8 CR3: 0000000028eec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	f6 0f 94             	testb  $0x94,(%rdi)
   3:	c0 4c 8b 75 00       	rorb   $0x0,0x75(%rbx,%rcx,4)
   8:	8d 54 00 01          	lea    0x1(%rax,%rax,1),%edx
   c:	b8 01 00 00 00       	mov    $0x1,%eax
  11:	bd 07 00 00 00       	mov    $0x7,%ebp
  16:	0f 44 e8             	cmove  %eax,%ebp
  19:	4c 89 f0             	mov    %r14,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  27:	fc ff df
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 82 06 00 00    	jne    0x6b9
  37:	41 89 16             	mov    %edx,(%r14)
  3a:	42 0f b6 04 23       	movzbl (%rbx,%r12,1),%eax
  3f:	84                   	.byte 0x84

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/29 06:03 linux-6.1.y 75cefdf153f5 865ef71e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in llc_conn_state_process
* Struck through repros no longer work on HEAD.