From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>,
Kairui Song <kasong@tencent.com>
Cc: linux-mm@kvack.org, Minchan Kim <minchan@kernel.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
Desheng Wu <deshengwu@tencent.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 1/2] zram: refuse to use zero sized block device as backing device
Date: Thu, 5 Dec 2024 16:05:52 +0900 [thread overview]
Message-ID: <20241205070552.GE16709@google.com> (raw)
In-Reply-To: <20241204180224.31069-2-ryncsn@gmail.com>
On (24/12/05 02:02), Kairui Song wrote:
> From: Kairui Song <kasong@tencent.com>
>
> Setting a zero sized block device as backing device is pointless, and
> one can easily create a recursive loop by setting the uninitialized
> ZRAM device itself as its own backing device by (zram0 is uninitialized):
>
> echo /dev/zram0 > /sys/block/zram0/backing_dev
>
> It's definitely a wrong config, and the module will pin itself,
> kernel should refuse doing so in the first place.
>
> By refusing to use zero sized device we avoided misuse cases
> including this one above.
>
> Fixes: 013bf95a83ec ("zram: add interface to specif backing device")
> Reported-by: Desheng Wu <deshengwu@tencent.com>
> Signed-off-by: Kairui Song <kasong@tencent.com>
> Cc: stable@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
next prev parent reply other threads:[~2024-12-05 7:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-04 18:02 [PATCH 0/2] zram: fix backing device setup issue Kairui Song
2024-12-04 18:02 ` [PATCH 1/2] zram: refuse to use zero sized block device as backing device Kairui Song
2024-12-05 7:05 ` Sergey Senozhatsky [this message]
2024-12-04 18:02 ` [PATCH 2/2] zram: fix uninitialized ZRAM not releasing " Kairui Song
2024-12-05 7:09 ` Sergey Senozhatsky
2024-12-09 16:52 ` Kairui Song
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