Re: [edk2-platforms][PATCH v3 03/11] Ext4Pkg: Fix division by zero by adding check for s_inodes_per_group

["Marvin Häuser" <mhaeuser@posteo.de>]

Reviewed-by: Marvin Häuser <mhaeuser@posteo.de>

> On 27. Jan 2023, at 15:13, Pedro Falcato <pedro.falcato@gmail.com> wrote:
> 
> On Fri, Jan 27, 2023 at 9:29 AM Savva Mitrofanov <savvamtr@gmail.com> wrote:
>> 
>> Superblock s_inodes_per_group field can't be zero, it leads to division
>> by zero in BlockGroup routine Ext4ReadInode
>> 
>> Cc: Marvin Häuser <mhaeuser@posteo.de>
>> Cc: Pedro Falcato <pedro.falcato@gmail.com>
>> Cc: Vitaly Cheptsov <vit9696@protonmail.com>
>> Fixes: d9ceedca6c8f ("Ext4Pkg: Add Ext4Dxe driver.")
>> Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
>> ---
>> Features/Ext4Pkg/Ext4Dxe/Superblock.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>> 
>> diff --git a/Features/Ext4Pkg/Ext4Dxe/Superblock.c b/Features/Ext4Pkg/Ext4Dxe/Superblock.c
>> index 35dcf3c007c8..be3527e4d618 100644
>> --- a/Features/Ext4Pkg/Ext4Dxe/Superblock.c
>> +++ b/Features/Ext4Pkg/Ext4Dxe/Superblock.c
>> @@ -243,6 +243,11 @@ Ext4OpenSuperblock (
>> 
>>   DEBUG ((DEBUG_FS, "Read only = %u\n", Partition->ReadOnly));
>> 
>> +  if (Sb->s_inodes_per_group == 0) {
>> +    DEBUG ((DEBUG_ERROR, "[ext4] Inodes per group can not be zero\n"));
>> +    return EFI_VOLUME_CORRUPTED;
>> +  }
>> +
>>   Partition->BlockSize = (UINT32)LShiftU64 (1024, Sb->s_log_block_size);
>> 
>>   // The size of a block group can also be calculated as 8 * Partition->BlockSize
>> --
>> 2.39.0
>> 
> 
> Reviewed-by: Pedro Falcato <pedro.falcato@gmail.com>
> 
> -- 
> Pedro