[edk2-platforms][PATCH v4 03/12] Ext4Pkg: Fix division by zero by adding check for s_inodes_per_group

["Savva Mitrofanov" <savvamtr@gmail.com>]

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>
Reviewed-by: Pedro Falcato <pedro.falcato@gmail.com>
Reviewed-by: Marvin Häuser <mhaeuser@posteo.de>
---
 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
-- 
2.39.1