Re: [syzbot] linux-next boot error: general protection fault in bio_add_hw_page

[Stephen Rothwell]

Hi syzbot,

On Mon, 26 Apr 2021 13:37:17 -0700 syzbot <syzbot+27916005c4a9d0d06bce@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot found the following issue on:
> 
> HEAD commit:    3f1fee3e Add linux-next specific files for 20210426
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=12103059d00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=286cd40bcb4d1f3a
> dashboard link: https://syzkaller.appspot.com/bug?extid=27916005c4a9d0d06bce
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+27916005c4a9d0d06bce@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> general protection fault, probably for non-canonical address 0xdffffc00000000c5: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000628-0x000000000000062f]
> CPU: 0 PID: 86 Comm: kworker/u4:2 Not tainted 5.12.0-next-20210426-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events_unbound async_run_entry_fn
> RIP: 0010:bio_max_size block/bio.c:260 [inline]
> RIP: 0010:bio_full include/linux/bio.h:124 [inline]
> RIP: 0010:bio_full include/linux/bio.h:119 [inline]
> RIP: 0010:bio_add_hw_page+0x198/0x830 block/bio.c:778
> Code: 48 c1 e9 03 80 3c 01 00 0f 85 b1 05 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 43 08 48 8d b8 28 06 00 00 48 89 fe 48 c1 ee 03 <80> 3c 0e 00 0f 85 9d 05 00 00 48 8b 80 28 06 00 00 48 b9 00 00 00
> RSP: 0000:ffffc900010cf6a8 EFLAGS: 00010206
> RAX: 0000000000000000 RBX: ffff8880133ffc00 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 00000000000000c5 RDI: 0000000000000628
> RBP: 0000000000000024 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff83b75207 R11: 0000000000000001 R12: 0000000000000000
> R13: ffff88801b594560 R14: 0000000000000000 R15: ffffea00050de340
> FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 000000000bc8e000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  bio_add_pc_page+0xb8/0x100 block/bio.c:812
>  bio_map_kern block/blk-map.c:374 [inline]
>  blk_rq_map_kern+0x2bd/0x750 block/blk-map.c:642
>  __scsi_execute+0x4c1/0x600 drivers/scsi/scsi_lib.c:224
>  scsi_execute_req include/scsi/scsi_device.h:462 [inline]
>  scsi_probe_lun drivers/scsi/scsi_scan.c:610 [inline]
>  scsi_probe_and_add_lun+0x521/0x34e0 drivers/scsi/scsi_scan.c:1104
>  __scsi_scan_target+0x21f/0xdb0 drivers/scsi/scsi_scan.c:1578
>  scsi_scan_channel drivers/scsi/scsi_scan.c:1666 [inline]
>  scsi_scan_channel+0x148/0x1e0 drivers/scsi/scsi_scan.c:1642
>  scsi_scan_host_selected+0x2df/0x3b0 drivers/scsi/scsi_scan.c:1695
>  do_scsi_scan_host+0x1e8/0x260 drivers/scsi/scsi_scan.c:1834
>  do_scan_async+0x3e/0x500 drivers/scsi/scsi_scan.c:1844
>  async_run_entry_fn+0x9d/0x550 kernel/async.c:127
>  process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
>  worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
>  kthread+0x3b1/0x4a0 kernel/kthread.c:313
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> Modules linked in:
> ---[ end trace a9f7e41e48b80dca ]---
> RIP: 0010:bio_max_size block/bio.c:260 [inline]
> RIP: 0010:bio_full include/linux/bio.h:124 [inline]
> RIP: 0010:bio_full include/linux/bio.h:119 [inline]
> RIP: 0010:bio_add_hw_page+0x198/0x830 block/bio.c:778
> Code: 48 c1 e9 03 80 3c 01 00 0f 85 b1 05 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 43 08 48 8d b8 28 06 00 00 48 89 fe 48 c1 ee 03 <80> 3c 0e 00 0f 85 9d 05 00 00 48 8b 80 28 06 00 00 48 b9 00 00 00
> RSP: 0000:ffffc900010cf6a8 EFLAGS: 00010206
> RAX: 0000000000000000 RBX: ffff8880133ffc00 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 00000000000000c5 RDI: 0000000000000628
> RBP: 0000000000000024 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff83b75207 R11: 0000000000000001 R12: 0000000000000000
> R13: ffff88801b594560 R14: 0000000000000000 R15: ffffea00050de340
> FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 000000000bc8e000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> 
> 
> ---
> 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.

This probably should be fixed today with the removal of commit

  42fb54fbc707 ("bio: limit bio max size")

-- 
Cheers,
Stephen Rothwell

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