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Date:   Thu, 3 Nov 2022 17:33:12 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Liu Shixin <liushixin2@huawei.com>
Cc:     Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>, linux-btrfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] btrfs: fix match incorrectly in dev_args_match_device
Message-ID: <20221103163312.GO5824@twin.jikos.cz>
Reply-To: dsterba@suse.cz
References: <20221103083301.626561-1-liushixin2@huawei.com>
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On Thu, Nov 03, 2022 at 04:33:01PM +0800, Liu Shixin wrote:
> syzkaller found an assert failed:
> 
>  assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921
> 
> This can be trigger when we set devid to (u64)-1) by ioctl. In this case,
> the match of devid will be skipped and the match of device may be succeed
> incorrectly.
> 
> Patch 562d7b1512f7 introduced this function which is used to match device.
> This function contaions two matching scenarios, we can distinguish them by
> checking the value of args->missing rather than check whether args->devid
> and args->uuid is default value.
> 
> Reported-by: syzbot+031687116258450f9853@syzkaller.appspotmail.com
> Fixes: 562d7b1512f7 ("btrfs: handle device lookup with btrfs_dev_lookup_args")
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>

Added to misc-next, thanks.