Re: [syzbot] [mtd?] divide error in block2mtd_setup2

在 2026/8/10 10:03, Jörn Engel 写道:
> 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!
Thank you for your contribution. I have sent this patch, but I forgot to
add the Suggested-by: tag

Thanks！
Pei.
> 
> Jörn
> 
> --
> Those who come seeking peace without a treaty are plotting.
> -- Sun Tzu
> 
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> Date: Sun, 9 Aug 2026 19:03:22 -0700
> From: =so-8859-1?Q?Jörn?= Engel <[email protected]>
> To: syzbot <[email protected]>
> Cc: [email protected], [email protected],
> 	[email protected], [email protected],
> 	[email protected], [email protected], [email protected]
> Subject: Re: [syzbot] [mtd?] divide error in block2mtd_setup2
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> 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
>