Re: [PATCH] qede: Prevent possible snprintf() truncation by bounding %s string format

[Baran TUna <barant@fastmail.com>]

The current solution is pretty arbitrary.

Numbers are coming from a simple calculation, to make sure output always 
fits.


I will take a further look and send a patch if there is a more 
generalized solution.

On 7/1/26 6:27 PM, Breno Leitao wrote:
> On Wed, Jul 01, 2026 at 05:47:11PM +0300, Baran Tuna wrote:
>> GCC warning shows that formatted strings may
>> exceed the fixed-size destination buffers.
>>
>> Bounding the %s string format
>> so the maximum formatted output always fits.
>>
>> This eliminates the -Wformat-truncation warning.
>>
>> Signed-off-by: Baran Tuna <barant@fastmail.com>
>> ---
>>   drivers/net/ethernet/qlogic/qede/qede_ethtool.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
>> index 647f30a16a94..5428f53150a0 100644
>> --- a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
>> +++ b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
>> @@ -618,10 +618,10 @@ static void qede_get_drvinfo(struct net_device *ndev,
>>   	if ((strlen(storm) + strlen("[storm]")) <
>>   	    sizeof(info->version))
>>   		snprintf(info->version, sizeof(info->version),
>> -			 "[storm %s]", storm);
>> +			 "[storm %.16s]", storm);
> Where is this 16 coming from?
>
> Also, isn't the if above checking for no overflow? I.e,
> we got here only if strlen(storm) + strlen("[storm]") < sizeof(info->version))
>
> For whoever else is reviwewing this, this the buffers:
>
> 	#define ETHTOOL_FWVERS_LEN      32
>          char    version[32];
> 	char storm[ETHTOOL_FWVERS_LEN];
>