syzbot


general protection fault in llc_conn_state_process (3)

Status: upstream: reported on 2025/05/20 18:10
Reported-by: syzbot+689ea515ca3b1b7aa9ca@syzkaller.appspotmail.com
First crash: 52d, last: 2d00h
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 general protection fault in llc_conn_state_process (2) 2 1 164d 164d 0/3 auto-obsoleted due to no activity on 2025/05/09 06:03
upstream UBSAN: array-index-out-of-bounds in llc_conn_state_process (2) net 15 21 6d06h 403d 0/29 upstream: reported on 2024/06/03 15:59
linux-6.1 general protection fault in llc_conn_state_process 2 1 317d 317d 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 17 2 1218d 1332d 0/29 auto-closed as invalid on 2022/07/10 02:25
linux-5.15 KASAN: global-out-of-bounds Read in llc_conn_state_process 17 1 527d 527d 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: 1 PID: 4739 Comm: syz.4.71 Not tainted 6.1.143-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:llc_conn_state_process+0xcba/0x1290 net/llc/llc_conn.c:-1
Code: 84 db 0f 94 c0 4d 8b 36 8d 54 00 01 b8 01 00 00 00 bd 07 00 00 00 0f 44 e8 4c 89 f0 48 c1 e8 03 48 bb 00 00 00 00 00 fc ff df <0f> b6 04 18 84 c0 0f 85 7e 05 00 00 41 89 16 41 0f b6 04 1c 84 c0
RSP: 0018:ffffc900001e0aa8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000100
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000007 R08: ffff88802df85940 R09: 0000000000000005
R10: 0000000000000005 R11: 0000000000000100 R12: 1ffff1100ade9202
R13: ffff888056f49000 R14: 0000000000000000 R15: ffff888056f49012
FS:  00007f8f7bbff6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001d000 CR3: 000000005018b000 CR4: 00000000003506e0
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+0x336/0x8a0 net/llc/llc_c_ac.c:1331
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 e9 e8 04 00 00 4c 8b 75 d0 4c 89 e7 e8 90 66 c9 08 e8 8b c1 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90005edf658 EFLAGS: 00000282
RAX: fbc8bfa32cb60a00 RBX: 0000000000000000 RCX: fbc8bfa32cb60a00
RDX: dffffc0000000000 RSI: ffffffff8a8bffe0 RDI: ffffffff8adf1720
RBP: ffffc90005edf6b0 R08: dffffc0000000000 R09: ffffed10171c7551
R10: ffffed10171c7551 R11: 1ffff110171c7550 R12: ffff88802df85940
R13: dffffc0000000000 R14: ffff888017731dc0 R15: ffff8880b8f3b550
 context_switch kernel/sched/core.c:5247 [inline]
 __schedule+0x10f1/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x97/0x280 kernel/time/timer.c:1941
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x2b9/0x590 kernel/sched/completion.c:138
 rdmsr_safe_on_cpu+0x139/0x210 arch/x86/lib/msr-smp.c:183
 msr_read+0x10a/0x1b0 arch/x86/kernel/msr.c:67
 vfs_read+0x2c0/0x920 fs/read_write.c:468
 ksys_read+0x143/0x240 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8f7bd8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8f7bbff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f8f7bfb5fa0 RCX: 00007f8f7bd8e929
RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000004
RBP: 00007f8f7be10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8f7bfb5fa0 R15: 00007ffde76a3778
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:llc_conn_state_process+0xcba/0x1290 net/llc/llc_conn.c:-1
Code: 84 db 0f 94 c0 4d 8b 36 8d 54 00 01 b8 01 00 00 00 bd 07 00 00 00 0f 44 e8 4c 89 f0 48 c1 e8 03 48 bb 00 00 00 00 00 fc ff df <0f> b6 04 18 84 c0 0f 85 7e 05 00 00 41 89 16 41 0f b6 04 1c 84 c0
RSP: 0018:ffffc900001e0aa8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000100
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000007 R08: ffff88802df85940 R09: 0000000000000005
R10: 0000000000000005 R11: 0000000000000100 R12: 1ffff1100ade9202
R13: ffff888056f49000 R14: 0000000000000000 R15: ffff888056f49012
FS:  00007f8f7bbff6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001d000 CR3: 000000005018b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	84 db                	test   %bl,%bl
   2:	0f 94 c0             	sete   %al
   5:	4d 8b 36             	mov    (%r14),%r14
   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:	48 bb 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbx
  27:	fc ff df
* 2a:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 7e 05 00 00    	jne    0x5b4
  36:	41 89 16             	mov    %edx,(%r14)
  39:	41 0f b6 04 1c       	movzbl (%r12,%rbx,1),%eax
  3e:	84 c0                	test   %al,%al

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/10 08:50 linux-6.1.y 04d1ccaa9c28 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in llc_conn_state_process
2025/05/20 18:09 linux-6.1.y 325285d9fc86 b47f9e02 .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.