[syzbot] [x25?] [reiserfs?] general protection fault in lapbeth_data_transmit

[syzbot] [x25?] [reiserfs?] general protection fault in lapbeth_data_transmit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    1b29d271614a Merge tag 'staging-6.4-rc7' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11028640a80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ac246111fb601aec
dashboard link: https://syzkaller.appspot.com/bug?extid=6062afbf92a14f75d88b
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=150a0f73280000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=107fcaff280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16519d7a3fc8/disk-1b29d271.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d2cd6e97f1df/vmlinux-1b29d271.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a7781abe10c9/bzImage-1b29d271.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/5b429fa9e0f3/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6062afbf92a14f75d88b@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0011ad8e6f: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x000000008d6c7378-0x000000008d6c737f]
CPU: 0 PID: 4991 Comm: syz-executor335 Not tainted 6.4.0-rc6-syzkaller-00269-g1b29d271614a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:dev_hard_header include/linux/netdevice.h:3137 [inline]
RIP: 0010:lapbeth_data_transmit+0x245/0x360 drivers/net/wan/lapbether.c:257
Code: 74 08 3c 01 0f 8e 97 00 00 00 49 8d bc 24 38 02 00 00 66 89 9d b8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c6 00 00 00 49 8b 9c 24 38 02 00 00 48 85 db 74
RSP: 0018:ffffc90000007c20 EFLAGS: 00010216
RAX: dffffc0000000000 RBX: 0000000000000012 RCX: 0000000000000003
RDX: 0000000011ad8e6f RSI: ffffffff8807bdbb RDI: 000000008d6c7378
RBP: ffff8880223bddc0 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000094001 R12: 000000008d6c7140
R13: 0000000000000000 R14: ffff888023302a14 R15: 0000000000000000
FS:  00005555563323c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055727dd5a800 CR3: 000000002921e000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 lapb_data_transmit+0x93/0xc0 net/lapb/lapb_iface.c:447
 lapb_transmit_buffer+0x187/0x3a0 net/lapb/lapb_out.c:149
 lapb_send_control+0x1cb/0x370 net/lapb/lapb_subr.c:251
 lapb_t1timer_expiry+0x5e0/0x8f0 net/lapb/lapb_timer.c:142
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers+0x29b/0x4b0 kernel/time/timer.c:1751
 __run_timers kernel/time/timer.c:2022 [inline]
 __run_timers kernel/time/timer.c:1995 [inline]
 run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035
 __do_softirq+0x1d4/0x905 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:memmove+0x4f/0x1b0 arch/x86/lib/memmove_64.S:69
Code: 0f 1f 44 00 00 48 81 fa a8 02 00 00 72 05 40 38 fe 74 48 48 83 ea 20 48 83 ea 20 4c 8b 1e 4c 8b 56 08 4c 8b 4e 10 4c 8b 46 18 <48> 8d 76 20 4c 89 1f 4c 89 57 08 4c 89 4f 10 4c 89 47 18 48 8d 7f
RSP: 0018:ffffc90003abefb0 EFLAGS: 00000286
RAX: ffff888073551fb4 RBX: 0000000000000002 RCX: 1ffff1100e6aa201
RDX: fffffffff9171f60 RSI: ffff88807a3dffe4 RDI: ffff88807a3dfff4
RBP: 0000000000000020 R08: 7a3e0c8000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: ffff888073551fa4 R15: 0000000000000010
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dev_hard_header include/linux/netdevice.h:3137 [inline]
RIP: 0010:lapbeth_data_transmit+0x245/0x360 drivers/net/wan/lapbether.c:257
Code: 74 08 3c 01 0f 8e 97 00 00 00 49 8d bc 24 38 02 00 00 66 89 9d b8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c6 00 00 00 49 8b 9c 24 38 02 00 00 48 85 db 74
RSP: 0018:ffffc90000007c20 EFLAGS: 00010216

RAX: dffffc0000000000 RBX: 0000000000000012 RCX: 0000000000000003
RDX: 0000000011ad8e6f RSI: ffffffff8807bdbb RDI: 000000008d6c7378
RBP: ffff8880223bddc0 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000094001 R12: 000000008d6c7140
R13: 0000000000000000 R14: ffff888023302a14 R15: 0000000000000000
FS:  00005555563323c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055727dd5a800 CR3: 000000002921e000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	3c 01                	cmp    $0x1,%al
   4:	0f 8e 97 00 00 00    	jle    0xa1
   a:	49 8d bc 24 38 02 00 	lea    0x238(%r12),%rdi
  11:	00
  12:	66 89 9d b8 00 00 00 	mov    %bx,0xb8(%rbp)
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 c6 00 00 00    	jne    0xfa
  34:	49 8b 9c 24 38 02 00 	mov    0x238(%r12),%rbx
  3b:	00
  3c:	48 85 db             	test   %rbx,%rbx
  3f:	74                   	.byte 0x74


---
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Re: [syzbot] [x25?] [reiserfs?] general protection fault in lapbeth_data_transmit

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <jack@suse.cz>
Date:   Wed Nov 1 17:43:10 2023 +0000

    fs: Block writes to mounted block devices

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=12dcaac4180000
start commit:   1b29d271614a Merge tag 'staging-6.4-rc7' of git://git.kern..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ac246111fb601aec
dashboard link: https://syzkaller.appspot.com/bug?extid=6062afbf92a14f75d88b
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=150a0f73280000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=107fcaff280000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: fs: Block writes to mounted block devices

For information about bisection process see: https://goo.gl/tpsmEJ#bisection