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: 11d, last: 11d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 general protection fault in llc_conn_state_process (2) 1 122d 122d 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 19 12d 362d 0/28 upstream: reported on 2024/06/03 15:59
linux-6.1 general protection fault in llc_conn_state_process 1 276d 276d 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 1176d 1290d 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 486d 486d 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: 4672 Comm: syz.2.71 Not tainted 6.1.139-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: ffff88801c3a3b80 R09: 0000000000000005
R10: 0000000000000005 R11: 0000000000000100 R12: 1ffff1100b42d002
R13: ffff88805a168000 R14: 0000000000000000 R15: ffff88805a168012
FS:  00007fd0c2c656c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557c6e2808 CR3: 0000000028b91000 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:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:661
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:673
 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:__sanitizer_cov_trace_pc+0x53/0x60 kernel/kcov.c:232
Code: 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a <48> 89 44 f2 08 c3 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 c4
RSP: 0018:ffffc9000505f900 EFLAGS: 00000283
RAX: ffffffff8407a78b RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000d731000 RSI: 000000000000f5f6 RDI: 000000000000f5f7
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100978803f
R10: ffffed100978803f R11: 1ffff1100978803e R12: 00007fffffffefff
R13: ffff88804bc401f0 R14: ffff88804bc401f0 R15: 0000000000000000
 _copy_from_user+0x10b/0x170 lib/usercopy.c:26
 copy_from_user include/linux/uaccess.h:161 [inline]
 snd_rawmidi_kernel_write1+0x353/0x590 sound/core/rawmidi.c:1549
 snd_rawmidi_write+0x568/0xb00 sound/core/rawmidi.c:1618
 do_loop_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x497/0xaf0 fs/read_write.c:863
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x24e/0x410 fs/read_write.c:977
 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: 0033:0x7fd0c1d8e969
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:00007fd0c2c65038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fd0c1fb5fa0 RCX: 00007fd0c1d8e969
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000004
RBP: 00007fd0c1e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd0c1fb5fa0 R15: 00007fff5a7b15e8
 </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: ffff88801c3a3b80 R09: 0000000000000005
R10: 0000000000000005 R11: 0000000000000100 R12: 1ffff1100b42d002
R13: ffff88805a168000 R14: 0000000000000000 R15: ffff88805a168012
FS:  00007fd0c2c656c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557c6e2808 CR3: 0000000028b91000 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 (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.