[LTP] [PATCH] genload: fix memory corruption in hogvm

[Jiwei Sun]

Hi Cyril,

On 6/11/24 20:11, Cyril Hrubis wrote:
> Hi!
>> Signed-off-by: Jiwei Sun <sunjw10@lenovo.com>
>> ---
>>  tools/genload/genload.c | 2 +-
>>  tools/genload/stress.c  | 2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/genload/genload.c b/tools/genload/genload.c
>> index 7f56d5272..9712e7828 100644
>> --- a/tools/genload/genload.c
>> +++ b/tools/genload/genload.c
>> @@ -642,7 +642,7 @@ int hogvm(long long forks, long long chunks, long long bytes)
>>  			usleep(backoff);
>>  
>>  			while (1) {
>> -				ptr = (char **)malloc(chunks * 2);
>> +				ptr = (char **)malloc(chunks * 2 * sizeof(char *));
> 
> Good catch, however shouldn't this be just chunks * sizeof(char*) ?

Yes indeed, totally agree with you, "* 2" is redundant, 
thanks for your review and reply. And also, if the chunks is 0, 
the memory will be corrupted too. I will modify it in the v2 patch.

Thanks,
Regards,
Jiwei

> 
>>  				for (j = 0; chunks == 0 || j < chunks; j++) {
>>  					if ((ptr[j] =
>>  					     (char *)malloc(bytes *
>> diff --git a/tools/genload/stress.c b/tools/genload/stress.c
>> index 7f56d5272..9712e7828 100644
>> --- a/tools/genload/stress.c
>> +++ b/tools/genload/stress.c
>> @@ -642,7 +642,7 @@ int hogvm(long long forks, long long chunks, long long bytes)
>>  			usleep(backoff);
>>  
>>  			while (1) {
>> -				ptr = (char **)malloc(chunks * 2);
>> +				ptr = (char **)malloc(chunks * 2 * sizeof(char *));
> 
> Here as well.
> 
>>  				for (j = 0; chunks == 0 || j < chunks; j++) {
>>  					if ((ptr[j] =
>>  					     (char *)malloc(bytes *
>> -- 
>> 2.27.0
>>
>>
>> -- 
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>