syzbot


general protection fault in n_tty_receive_buf_common (2)

Status: moderation: reported on 2024/03/08 06:32
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+7e8ce8432b7ba3c3388c@syzkaller.appspotmail.com
First crash: 43d, last: 1d17h
Similar bugs (3)
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 272d 853d 0/26 auto-obsoleted due to no activity on 2023/09/27 16:27
android-6-1 general protection fault in n_tty_receive_buf_common 1 54d 54d 0/2 premoderation: reported on 2024/02/22 15:26
upstream general protection fault in n_tty_receive_buf_common serial 48 1980d 2363d 0/26 closed as dup on 2018/07/17 10:20

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000044c: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000000002260-0x0000000000002267]
CPU: 0 PID: 42 Comm: kworker/u8:2 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:n_tty_receive_buf_common+0x136/0x12c0 drivers/tty/n_tty.c:1708
Code: 00 45 31 ed 48 89 8c 24 e0 00 00 00 48 c1 e9 03 48 89 8c 24 e8 00 00 00 48 89 5c 24 68 4c 89 6c 24 08 48 8b 84 24 e8 00 00 00 <42> 80 3c 30 00 74 0d 48 8b bc 24 e0 00 00 00 e8 e6 2b d7 fc 4c 89
RSP: 0018:ffffc90000b279a8 EFLAGS: 00010202
RAX: 000000000000044c RBX: ffff88807f369438 RCX: 000000000000044c
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88807f369287 R09: 1ffff1100fe6d250
R10: dffffc0000000000 R11: ffffed100fe6d251 R12: ffff8880203b9020
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880203b9020
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558a191ba000 CR3: 00000000476d4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:444 [inline]
 flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:494
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:n_tty_receive_buf_common+0x136/0x12c0 drivers/tty/n_tty.c:1708
Code: 00 45 31 ed 48 89 8c 24 e0 00 00 00 48 c1 e9 03 48 89 8c 24 e8 00 00 00 48 89 5c 24 68 4c 89 6c 24 08 48 8b 84 24 e8 00 00 00 <42> 80 3c 30 00 74 0d 48 8b bc 24 e0 00 00 00 e8 e6 2b d7 fc 4c 89
RSP: 0018:ffffc90000b279a8 EFLAGS: 00010202
RAX: 000000000000044c RBX: ffff88807f369438 RCX: 000000000000044c
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88807f369287 R09: 1ffff1100fe6d250
R10: dffffc0000000000 R11: ffffed100fe6d251 R12: ffff8880203b9020
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880203b9020
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa881979198 CR3: 000000002e66c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 45 31             	add    %al,0x31(%rbp)
   3:	ed                   	in     (%dx),%eax
   4:	48 89 8c 24 e0 00 00 	mov    %rcx,0xe0(%rsp)
   b:	00
   c:	48 c1 e9 03          	shr    $0x3,%rcx
  10:	48 89 8c 24 e8 00 00 	mov    %rcx,0xe8(%rsp)
  17:	00
  18:	48 89 5c 24 68       	mov    %rbx,0x68(%rsp)
  1d:	4c 89 6c 24 08       	mov    %r13,0x8(%rsp)
  22:	48 8b 84 24 e8 00 00 	mov    0xe8(%rsp),%rax
  29:	00
* 2a:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1) <-- trapping instruction
  2f:	74 0d                	je     0x3e
  31:	48 8b bc 24 e0 00 00 	mov    0xe0(%rsp),%rdi
  38:	00
  39:	e8 e6 2b d7 fc       	call   0xfcd72c24
  3e:	4c                   	rex.WR
  3f:	89                   	.byte 0x89

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/15 03:06 upstream fe46a7dd189e c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root general protection fault in n_tty_receive_buf_common
2024/04/13 12:25 upstream fe46a7dd189e c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root general protection fault in n_tty_receive_buf_common
2024/03/04 06:26 upstream 58c806d867bf 25905f5d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce general protection fault in n_tty_receive_buf_common
* Struck through repros no longer work on HEAD.