Re: [PATCH v2] EDAC/thunderx: Fix some potential buffer overflow in thunderx_ocx_com_threaded_isr()

[Greg KH]

On Sat, Oct 21, 2023 at 07:13:51PM +0200, Christophe JAILLET wrote:
> strncat() usage in thunderx_ocx_com_threaded_isr() is wrong.
> The size given to strncat() is the maximum number of bytes that can be
> written, excluding the trailing NULL.
> 
> Here, the size of the 'msg' buffer is used (i.e. OCX_MESSAGE_SIZE), not
> the space that is remaining.
> The space for the ending NULL is also not taken into account.
> 
> in order to fix it:
>    - call decode_register() before the snprintf() calls
>    - use scnprintf() instead of snprintf() and compute, in the 'remaining'
>      variable, the space that is still available in the 'msg' buffer
>    - add a %s at the end of the format strings and append directly the
>      result of decode_register() stored in 'other'
>    - write directly at the right position in the 'msg' buffer when
>      appending some data in the for loop.
> 
> Doing so, all usages of strncat() are removed.
> 
> Fixes: 41003396f932 ("EDAC, thunderx: Add Cavium ThunderX EDAC driver")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> This is cross-compile tested only.
> Review with care.
> 
> v2: remove some other erroneous usage of strncat()
> ---
>  drivers/edac/thunderx_edac.c | 44 ++++++++++++++++--------------------
>  1 file changed, 20 insertions(+), 24 deletions(-)

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
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