syzbot


general protection fault in slip_receive_buf (2)

Status: moderation: reported on 2025/05/26 20:24
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+590bbadae11ce2193aa7@syzkaller.appspotmail.com
First crash: 7d13h, last: 7d13h
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in slip_receive_buf net 1 673d 669d 0/28 auto-obsoleted due to no activity on 2023/10/24 19:58

Sample crash report:
sl0: compressed packet ignored
sl0: compressed packet ignored
sl0: compressed packet ignored
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 3016 Comm: kworker/u4:12 Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:slip_unesc drivers/net/slip/slip.c:987 [inline]
RIP: 0010:slip_receive_buf+0x807/0xd60 drivers/net/slip/slip.c:709
Code: 4d 8b 6d 00 48 8b 44 24 20 0f b6 04 18 84 c0 0f 85 14 04 00 00 41 8d 44 24 01 48 8b 0c 24 89 01 4d 01 e5 4c 89 e8 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 13 04 00 00 41 88 6d 00 4c 8b 6c 24 08 48
RSP: 0018:ffffc9000d75f968 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888043676e38
RDX: 0000000000000000 RSI: 0000000000000480 RDI: 0000000000000000
RBP: 000000000000002c R08: ffff888043676e6f R09: 1ffff110086cedcd
R10: dffffc0000000000 R11: ffffed10086cedce R12: 0000000000000000
R13: 0000000000000000 R14: 000000000000050f R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9d75620440 CR3: 0000000041ed7000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tty_ldisc_receive_buf+0x116/0x160 drivers/tty/tty_buffer.c:391
 tty_port_default_receive_buf+0x6e/0xa0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x2c5/0x810 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:slip_unesc drivers/net/slip/slip.c:987 [inline]
RIP: 0010:slip_receive_buf+0x807/0xd60 drivers/net/slip/slip.c:709
Code: 4d 8b 6d 00 48 8b 44 24 20 0f b6 04 18 84 c0 0f 85 14 04 00 00 41 8d 44 24 01 48 8b 0c 24 89 01 4d 01 e5 4c 89 e8 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 13 04 00 00 41 88 6d 00 4c 8b 6c 24 08 48
RSP: 0018:ffffc9000d75f968 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888043676e38
RDX: 0000000000000000 RSI: 0000000000000480 RDI: 0000000000000000
RBP: 000000000000002c R08: ffff888043676e6f R09: 1ffff110086cedcd
R10: dffffc0000000000 R11: ffffed10086cedce R12: 0000000000000000
R13: 0000000000000000 R14: 000000000000050f R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88808d6c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc1050a3d8 CR3: 000000003ef24000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	4d 8b 6d 00          	mov    0x0(%r13),%r13
   4:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   9:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax
   d:	84 c0                	test   %al,%al
   f:	0f 85 14 04 00 00    	jne    0x429
  15:	41 8d 44 24 01       	lea    0x1(%r12),%eax
  1a:	48 8b 0c 24          	mov    (%rsp),%rcx
  1e:	89 01                	mov    %eax,(%rcx)
  20:	4d 01 e5             	add    %r12,%r13
  23:	4c 89 e8             	mov    %r13,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 13 04 00 00    	jne    0x449
  36:	41 88 6d 00          	mov    %bpl,0x0(%r13)
  3a:	4c 8b 6c 24 08       	mov    0x8(%rsp),%r13
  3f:	48                   	rex.W

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/22 20:23 upstream 5cdb2c77c4c3 0919b50b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in slip_receive_buf
* Struck through repros no longer work on HEAD.