[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+6062af...@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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[syzbot]

syzbot suspects this issue was fixed by commit:

commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <ja...@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

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.