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From: shichao lai <shichaorai@gmail.com>
Date: Sat, 25 May 2024 12:35:07 +0800
Message-ID: <CACjpba4d6i99_NcoShrfsZztzjzBQaL1nDC5WMTj2eBuMoaoZQ@mail.gmail.com>
Subject: Re: [PATCHv2] Check whether divisor is non-zero before division
To: Alan Stern <stern@rowland.harvard.edu>, gregkh@linuxfoundation.org, oneukum@suse.com
Cc: linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, 
	linux-kernel@vger.kernel.org, xingwei lee <xrivendell7@gmail.com>, 
	yue sun <samsun1006219@gmail.com>
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On Sat, May 25, 2024 at 10:24=E2=80=AFAM Alan Stern <stern@rowland.harvard.=
edu> wrote:
> If alauda_init_media() returns an error, leave info->initialized
> unchanged.  alauda_check_media() will return an error also, so the bad
> division won't take place.
>
> Alan Stern

Thanks! You also remind me that the return value from
alauda_init_media() is never used!
By this way, the workflow now seems to work correctly.
It tries to initialize multiple times, and finally disconnects due to
no response.

Now if possible, I will post a [PATCH v4] for this bug soon.
I want to know whether it is possible to add some tags like
Suggested-by or Reviewed-by for Dear Alan Stern, gregkh
and oneukum as thanks for your discussions.

e.g.
=3D=3D=3D=3D kernel log
[   47.266129][ T4125] alauda_check_media: before init_media,
status[0]: 0000000000000036
[   47.266555][ T4125] alauda_check_media: enter init_media
[   47.467314][    T9] usb 1-1: USB disconnect, device number 2
root@syzkaller:~# [   47.485304][ T4125] alauda_get_media_status: data=3D54=
, rc=3D4
[   47.485640][ T4125] alauda_init_media: exit in 391
[   47.486104][   T41] sd 2:0:0:0: [sdb] Read Capacity(10) failed:
Result: hostbyte=3DDID_ERROR driverbyte=3DDRIVER_OK
[   47.486591][   T41] sd 2:0:0:0: [sdb] Sense not available.
[   47.486889][   T41] sd 2:0:0:0: [sdb] 0 512-byte logical blocks: (0 B/0 =
B)
[   47.487212][   T41] sd 2:0:0:0: [sdb] 0-byte physical blocks
[   47.487515][   T41] sd 2:0:0:0: [sdb] Write Protect is off
[   47.487813][   T41] sd 2:0:0:0: [sdb] Asking for cache data failed
[   47.488104][   T41] sd 2:0:0:0: [sdb] Assuming drive cache: write throug=
h
[   47.491396][   T41] sd 2:0:0:0: [sdb] Attached SCSI removable disk
[   48.105309][ T1198] not responding...