Hello, syzbot found the following issue on: HEAD commit: 39cd87c4eb2b Linux 6.9-rc2 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=133bffe6180000 kernel config: https://syzkaller.appspot.com/x/.config?x=8c2c72b264636e25 dashboard link: https://syzkaller.appspot.com/bug?extid=f3a09670f3d2a55b89b2 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-39cd87c4.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9e28c9b1ddc4/vmlinux-39cd87c4.xz kernel image: https://storage.googleapis.com/syzbot-assets/17cff5c46535/bzImage-39cd87c4.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f3a09670f3d2a55b89b2@xxxxxxxxxxxxxxxxxxxxxxxxx divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 2 PID: 7215 Comm: syz-executor.1 Not tainted 6.9.0-rc2-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:netfs_submit_writethrough+0x201/0x280 fs/netfs/output.c:427 Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1a 8b 8b 0c 01 00 00 48 89 e8 31 d2 <48> f7 f1 48 89 c5 48 0f af e9 e9 1d ff ff ff e8 6b 1c b9 ff eb df RSP: 0018:ffffc90001f1f740 EFLAGS: 00010246 RAX: 0000000000001000 RBX: ffff88801fd08c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff82317e29 RDI: ffff88801fd08d0c RBP: 0000000000001000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000000 R13: ffff8880545c2920 R14: ffff88801fd08d20 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88802c400000(0063) knlGS:00000000f5ecab40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002000f000 CR3: 0000000053f7e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> netfs_advance_writethrough+0x13f/0x170 fs/netfs/output.c:449 netfs_perform_write+0x1b9f/0x26b0 fs/netfs/buffered_write.c:385 netfs_buffered_write_iter_locked+0x213/0x2c0 fs/netfs/buffered_write.c:454 netfs_file_write_iter+0x1e0/0x470 fs/netfs/buffered_write.c:493 v9fs_file_write_iter+0xa1/0x100 fs/9p/vfs_file.c:407 call_write_iter include/linux/fs.h:2108 [inline] do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xdb0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7f/0x89 RIP: 0023:0xf72d0579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5eca5ac EFLAGS: 00000292 ORIG_RAX: 000000000000017b RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000020000780 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000016 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:netfs_submit_writethrough+0x201/0x280 fs/netfs/output.c:427 Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1a 8b 8b 0c 01 00 00 48 89 e8 31 d2 <48> f7 f1 48 89 c5 48 0f af e9 e9 1d ff ff ff e8 6b 1c b9 ff eb df RSP: 0018:ffffc90001f1f740 EFLAGS: 00010246 RAX: 0000000000001000 RBX: ffff88801fd08c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff82317e29 RDI: ffff88801fd08d0c RBP: 0000000000001000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000000 R13: ffff8880545c2920 R14: ffff88801fd08d20 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88802c400000(0063) knlGS:00000000f5ecab40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002000f000 CR3: 0000000053f7e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: df 48 89 fisttps -0x77(%rax) 3: fa cli 4: 48 c1 ea 03 shr $0x3,%rdx 8: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx c: 48 89 f8 mov %rdi,%rax f: 83 e0 07 and $0x7,%eax 12: 83 c0 03 add $0x3,%eax 15: 38 d0 cmp %dl,%al 17: 7c 04 jl 0x1d 19: 84 d2 test %dl,%dl 1b: 75 1a jne 0x37 1d: 8b 8b 0c 01 00 00 mov 0x10c(%rbx),%ecx 23: 48 89 e8 mov %rbp,%rax 26: 31 d2 xor %edx,%edx * 28: 48 f7 f1 div %rcx <-- trapping instruction 2b: 48 89 c5 mov %rax,%rbp 2e: 48 0f af e9 imul %rcx,%rbp 32: e9 1d ff ff ff jmp 0xffffff54 37: e8 6b 1c b9 ff call 0xffb91ca7 3c: eb df jmp 0x1d --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
