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Date:   Thu, 31 Mar 2022 16:42:10 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Wenchao Hao <haowenchao@huawei.com>,
        syzkaller-bugs@googlegroups.com
Cc:     fmdefrancesco@gmail.com, axboe@kernel.dk, jejb@linux.ibm.com,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
        syzbot+f08c77040fa163a75a46@syzkaller.appspotmail.com,
        syzkaller-bugs@googlegroups.com, linfeilong@huawei.com
Subject: Re: [PATCH] scsi: sd: call device_del() if device_add_disk() fails
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References: <20220329154948.10350-1-fmdefrancesco@gmail.com>
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 <20220331054156.GI3293@kadam>
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X-Mailing-List: linux-kernel@vger.kernel.org

Wenchao Hao, what you're saying makes a lot of sense but it raises a lot
of questions in turn.

Fabio, did you test your patch?

This is another reason why syzbot should display the whole dmesg because
otherwise we can't ask people link to their test results if it just says
"PASSED" with no additional information.  If syzbot provided a dmesg
at the end then I would require a link to it under the --- cut off
line for patches that I review.

In a way this gets back to the original testing that syzbot did do.  If
Wenchao's reading of the code is correct the Fabio's patch caused a
series of use after free bugs but because the test results just said
"PASSED" with no additional information.

Either way, failing to call device_del() is still a bug.

Also, I don't really understand why we don't have to call
put_device(&sdkp->disk_dev) at the end of sd_remove().

regards,
dan carpenter