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From: Richard Weinberger <richard@nod.at>
To: liu song11 <liu.song11@zte.com.cn>
Cc: Richard Weinberger <richard.weinberger@gmail.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	jiang xuexin <jiang.xuexin@zte.com.cn>
Subject: Re: [PATCH] ubifs: Fix potentially out-of-bounds memory access in ubifs_dump_node
Date: Mon, 13 Jan 2020 08:54:08 +0100 (CET)	[thread overview]
Message-ID: <1681702500.19692.1578902048331.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <202001131229371470661@zte.com.cn>

----- Ursprüngliche Mail -----
> Problems with storage devices are indeed a problem, But because the wrong
> "ch->len" causes the kernel to crash, this cost is too heavy. We should
> avoid kernel crashes due to such errors.
> 
> 
> Although a crc error was found in "ubifs_check_node", it is difficult to
> simply judge whether "ch->len" is reasonable, so I think we only need to know
> the _location_ of the error data node, and it is not necessary to present its
> contents together.

What we can try is optionally passing the buffer length to ubifs_dump_node().
If crc is bad but ch->len is within bounds we can still safely dump.

Thanks,
//richard

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: liu song11 <liu.song11@zte.com.cn>
Cc: Richard Weinberger <richard.weinberger@gmail.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	jiang xuexin <jiang.xuexin@zte.com.cn>
Subject: Re: [PATCH] ubifs: Fix potentially out-of-bounds memory access in ubifs_dump_node
Date: Mon, 13 Jan 2020 08:54:08 +0100 (CET)	[thread overview]
Message-ID: <1681702500.19692.1578902048331.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <202001131229371470661@zte.com.cn>

----- Ursprüngliche Mail -----
> Problems with storage devices are indeed a problem, But because the wrong
> "ch->len" causes the kernel to crash, this cost is too heavy. We should
> avoid kernel crashes due to such errors.
> 
> 
> Although a crc error was found in "ubifs_check_node", it is difficult to
> simply judge whether "ch->len" is reasonable, so I think we only need to know
> the _location_ of the error data node, and it is not necessary to present its
> contents together.

What we can try is optionally passing the buffer length to ubifs_dump_node().
If crc is bad but ch->len is within bounds we can still safely dump.

Thanks,
//richard

       reply	other threads:[~2020-01-13  7:54 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191216154441.6648-1-fishland@aliyun.com, CAFLxGvyU=zh23vkYiAGRzyd4LGJodLwRRa1S03THAoSaSL=dGA@mail.gmail.com>
     [not found] ` <202001131229371470661@zte.com.cn>
2020-01-13  7:54   ` Richard Weinberger [this message]
2020-01-13  7:54     ` [PATCH] ubifs: Fix potentially out-of-bounds memory access in ubifs_dump_node Richard Weinberger
2019-12-16 15:44 Liu Song
2020-01-12 22:49 ` Richard Weinberger
2020-01-12 22:49   ` Richard Weinberger

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