[PATCH] fastboot: mmc: Fix dest size in strlcat()

[Ariel D'Alessandro]

Hi Sean,

On 9/30/21 12:15 PM, Sean Anderson wrote:
> 
> 
> 
> On 9/30/21 9:47 AM, Ariel D'Alessandro wrote:
>> strlcat() is truncating the destination string to the size of the source
>> string. Fix size argument in strlcat() to match the size of destination
>> buffer.
>>
>> Bug was introduced in the following commit:
>>
>> commit 69a752983171c2983fc1f29c7cfa1844f41e5d8b
>> Author: Sean Anderson <seanga2 at gmail.com>
>>
>>      fastboot: Fix possible buffer overrun
>>
>> Signed-off-by: Ariel D'Alessandro <ariel.dalessandro at collabora.com>
>> ---
>>   drivers/fastboot/fb_mmc.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/fastboot/fb_mmc.c b/drivers/fastboot/fb_mmc.c
>> index cbb3f7b1dea..4c54f0c3893 100644
>> --- a/drivers/fastboot/fb_mmc.c
>> +++ b/drivers/fastboot/fb_mmc.c
>> @@ -40,7 +40,7 @@ static int raw_part_get_info_by_name(struct blk_desc
>> *dev_desc,
>>
>>       /* check for raw partition descriptor */
>>       strcpy(env_desc_name, "fastboot_raw_partition_");
>> -    strlcat(env_desc_name, name, PART_NAME_LEN);
>> +    strlcat(env_desc_name, name, ARRAY_SIZE(env_desc_name));
>>       raw_part_desc = strdup(env_get(env_desc_name));
>>       if (raw_part_desc == NULL)
>>           return -ENODEV;
>> @@ -114,7 +114,7 @@ static int part_get_info_by_name_or_alias(struct
>> blk_desc **dev_desc,
>>
>>           /* check for alias */
>>           strcpy(env_alias_name, "fastboot_partition_alias_");
>> -        strlcat(env_alias_name, name, PART_NAME_LEN);
>> +        strlcat(env_alias_name, name, ARRAY_SIZE(env_alias_name));
>>           aliased_part_name = env_get(env_alias_name);
>>           if (aliased_part_name != NULL)
>>               ret = do_get_part_info(dev_desc, aliased_part_name,
>>
> 
> This looks like a duplicate of [1]. I think the only difference is
> ARRAY_SIZE vs sizeof, but they are equivalent since sizeof(char) == 1.

Ah, you're right. Sorry I missed that patch.

> 
> --Sean
> 
> [1]
> http://patchwork.ozlabs.org/project/uboot/patch/20210730122354.6281-1-matthias.schiffer@ew.tq-group.com/
>