From: "Jörn Engel" <joern@barelysecure.org>
To: syzbot <syzbot+b320a4d5f65a61dbbf89@syzkaller.appspotmail.com>
Cc: joern@lazybastard.org, linux-kernel@vger.kernel.org,
linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com,
richard@nod.at, syzkaller-bugs@googlegroups.com, vigneshr@ti.com
Subject: Re: [syzbot] [mtd?] divide error in block2mtd_setup2
Date: Sun, 9 Aug 2026 19:03:22 -0700 [thread overview]
Message-ID: <ankxaiwtTltL0xMj@cashel.logfs.org> (raw)
In-Reply-To: <6a791c94.01d0871a.3a0d52.009b.GAE@google.com>
On Sun, Aug 09, 2026 at 05:34:28PM -0700, syzbot wrote:
>
> * 2a: f7 f6 div %esi <-- trapping instruction
Best guess would be this:
if ((long)size % erase_size) {
Someone passing an erase_size of 0 would indeed trigger an exception.
Fix would be something like this:
- if ((long)size % erase_size) {
+ if (!erase_size || (long)size % erase_size) {
I haven't touched the code is nearly two decades. If somebody else
feels like sending a patch and gathering all the glory, please be my
guest!
Jörn
--
Those who come seeking peace without a treaty are plotting.
-- Sun Tzu
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http://lists.infradead.org/mailman/listinfo/linux-mtd/
WARNING: multiple messages have this Message-ID (diff)
From: "Jörn Engel" <joern@barelysecure.org>
To: syzbot <syzbot+b320a4d5f65a61dbbf89@syzkaller.appspotmail.com>
Cc: joern@lazybastard.org, linux-kernel@vger.kernel.org,
linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com,
richard@nod.at, syzkaller-bugs@googlegroups.com, vigneshr@ti.com
Subject: Re: [syzbot] [mtd?] divide error in block2mtd_setup2
Date: Sun, 9 Aug 2026 19:03:22 -0700 [thread overview]
Message-ID: <ankxaiwtTltL0xMj@cashel.logfs.org> (raw)
In-Reply-To: <6a791c94.01d0871a.3a0d52.009b.GAE@google.com>
On Sun, Aug 09, 2026 at 05:34:28PM -0700, syzbot wrote:
>
> * 2a: f7 f6 div %esi <-- trapping instruction
Best guess would be this:
if ((long)size % erase_size) {
Someone passing an erase_size of 0 would indeed trigger an exception.
Fix would be something like this:
- if ((long)size % erase_size) {
+ if (!erase_size || (long)size % erase_size) {
I haven't touched the code is nearly two decades. If somebody else
feels like sending a patch and gathering all the glory, please be my
guest!
Jörn
--
Those who come seeking peace without a treaty are plotting.
-- Sun Tzu
next prev parent reply other threads:[~2026-08-10 2:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-10 0:34 [syzbot] [mtd?] divide error in block2mtd_setup2 syzbot
2026-08-10 0:34 ` syzbot
2026-08-10 2:03 ` Jörn Engel [this message]
2026-08-10 2:03 ` Jörn Engel
2026-08-10 9:17 ` Pei Xiao
2026-08-10 9:17 ` Pei Xiao
2026-08-10 12:40 ` Miquel Raynal
2026-08-10 12:40 ` Miquel Raynal
2026-08-11 3:02 ` Pei Xiao
2026-08-11 3:02 ` Pei Xiao
2026-08-10 16:27 ` Jörn Engel
2026-08-10 16:27 ` Jörn Engel
2026-08-11 1:21 ` Pei Xiao
2026-08-11 1:21 ` Pei Xiao
2026-08-10 9:12 ` [PATCH] mtd: block2mtd: Fix divide error when erase_size is zero Pei Xiao
2026-08-10 9:12 ` Pei Xiao
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