Re: [PATCH v4 1/5] staging: rtl8723bs: fix potential out-of-bounds read in rtw_restruct_wmm_ie

From: Dan Carpenter

Date: Fri Jan 30 2026 - 03:44:30 EST


Please, slow down. Only resend a patchset once per day.

On Thu, Jan 29, 2026 at 07:15:37PM +0100, Luka Gejak wrote:
> The current code checks 'i + 5 < in_len' at the end of
> the if statement.
> However, it accesses 'in_ie[i + 5]' before that check,
> which can lead to an out-of-bounds read.

The line breaks are weird looking. You're putting a new line between
sentences and a blank line between paragraphs. Just put a blank line
between paragraphs and delete the extra newline.

The out of bounds read is most likely going to be harmless. Hopefully,
it would be detected and trigger a warning from the UBSan type tools.
Also if you got really unlucky and in_ie[] was at the end of a page
then it could cause a crash.

This bug is still definitely worth fixing.

>
> Move the length check to the beginning of the conditional
> to ensure the index is within bounds before accessing the array.
>
> Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
>
> Cc: stable@xxxxxxxxxxxxxxx
>
> Signed-off-by: Luka Gejak <lukagejak5@xxxxxxxxx>

Delete the blank lines in the S-o-b block.

regards,
dan carpenter