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

["Pedro Falcato" <pedro.falcato@gmail.com>]

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