syzbot


general protection fault in n_tty_receive_buf_common

Status: upstream: reported on 2024/11/02 03:23
Reported-by: syzbot+736ee84d1b8778061573@syzkaller.appspotmail.com
First crash: 35d, last: 35d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in n_tty_receive_buf_common (2) serial C 591 506d 1088d 0/28 auto-obsoleted due to no activity on 2023/09/27 16:27
upstream general protection fault in n_tty_receive_buf_common (2) serial 11 5h08m 135d 0/28 upstream: reported on 2024/07/25 04:27
android-6-1 general protection fault in n_tty_receive_buf_common 1 288d 288d 0/2 auto-obsoleted due to no activity on 2024/05/22 15:27
upstream general protection fault in n_tty_receive_buf_common serial 48 2215d 2598d 0/28 closed as dup on 2018/07/17 10:20
android-6-1 general protection fault in n_tty_receive_buf_common (2) 4 67d 139d 0/2 premoderation: reported on 2024/07/21 14:40

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000044c: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000000000002260-0x0000000000002267]
CPU: 1 PID: 4350 Comm: kworker/u4:8 Not tainted 6.1.115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:n_tty_receive_buf_common+0x14a/0x13e0 drivers/tty/n_tty.c:1700
Code: 89 84 24 b0 00 00 00 48 bb 00 00 00 00 00 fc ff df 4c 89 6c 24 38 4c 89 74 24 30 48 8b bc 24 e8 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 18 00 74 05 e8 6b f9 38 fd 48 8b 9c 24 a0 00 00 00 4c 8b ab
RSP: 0018:ffffc900046f7a48 EFLAGS: 00010202
RAX: 000000000000044c RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffff8880279f9dc0 RSI: 0000000000000001 RDI: 0000000000002260
RBP: 0000000000000000 R08: ffffffff84a91c35 R09: ffffed100af78e51
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888079417020
R13: ffff888057bc75f8 R14: ffff888079417020 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020003000 CR3: 000000005a952000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tty_port_default_receive_buf+0x6a/0x90 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:515 [inline]
 flush_to_ldisc+0x2f4/0x840 drivers/tty/tty_buffer.c:565
 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:n_tty_receive_buf_common+0x14a/0x13e0 drivers/tty/n_tty.c:1700
Code: 89 84 24 b0 00 00 00 48 bb 00 00 00 00 00 fc ff df 4c 89 6c 24 38 4c 89 74 24 30 48 8b bc 24 e8 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 18 00 74 05 e8 6b f9 38 fd 48 8b 9c 24 a0 00 00 00 4c 8b ab
RSP: 0018:ffffc900046f7a48 EFLAGS: 00010202
RAX: 000000000000044c RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffff8880279f9dc0 RSI: 0000000000000001 RDI: 0000000000002260
RBP: 0000000000000000 R08: ffffffff84a91c35 R09: ffffed100af78e51
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888079417020
R13: ffff888057bc75f8 R14: ffff888079417020 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d01affc CR3: 000000005a03e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	89 84 24 b0 00 00 00 	mov    %eax,0xb0(%rsp)
   7:	48 bb 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbx
   e:	fc ff df
  11:	4c 89 6c 24 38       	mov    %r13,0x38(%rsp)
  16:	4c 89 74 24 30       	mov    %r14,0x30(%rsp)
  1b:	48 8b bc 24 e8 00 00 	mov    0xe8(%rsp),%rdi
  22:	00
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1) <-- trapping instruction
  2e:	74 05                	je     0x35
  30:	e8 6b f9 38 fd       	call   0xfd38f9a0
  35:	48 8b 9c 24 a0 00 00 	mov    0xa0(%rsp),%rbx
  3c:	00
  3d:	4c                   	rex.WR
  3e:	8b                   	.byte 0x8b
  3f:	ab                   	stos   %eax,%es:(%rdi)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/02 03:22 linux-6.1.y 7c15117f9468 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in n_tty_receive_buf_common
* Struck through repros no longer work on HEAD.