linux-kernel - Re: [PATCH] Check whether divisor is non-zero before division

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Thu, 23 May 2024 10:18:05 +0200
From: Oliver Neukum <oneukum@...e.com>
To: Shichao Lai <shichaorai@...il.com>, stern@...land.harvard.edu,
 gregkh@...uxfoundation.org
Cc: linux-usb@...r.kernel.org, usb-storage@...ts.one-eyed-alien.net,
 linux-kernel@...r.kernel.org, xingwei lee <xrivendell7@...il.com>,
 yue sun <samsun1006219@...il.com>
Subject: Re: [PATCH] Check whether divisor is non-zero before division

On 23.05.24 09:22, Shichao Lai wrote:

Hi,

> Since uzonesize may be zero, so a judgement for non-zero is nessesary.
> 
> Reported-by: xingwei lee <xrivendell7@...il.com>
> Reported-by: yue sun <samsun1006219@...il.com>
> Signed-off-by: Shichao Lai <shichaorai@...il.com>
> ---
>   drivers/usb/storage/alauda.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
> index 115f05a6201a..db075a8c03cb 100644
> --- a/drivers/usb/storage/alauda.c
> +++ b/drivers/usb/storage/alauda.c
> @@ -947,6 +947,8 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
>   	sg = NULL;
>   
>   	while (sectors > 0) {
> +		if (!uzonesize)
> +			return USB_STOR_TRANSPORT_ERROR;

May I point out that uzonesize does not change in this function?
There is no need to retest within the loop.

>   		unsigned int zone = lba / uzonesize; /* integer division */
>   		unsigned int lba_offset = lba - (zone * uzonesize);
>   		unsigned int pages;

Secondly, alauda_write_lba() has the same issue.
You also need to check in alauda_write_data().

	Regards
		Oliver