ext4: add sanity check to ext4_get_group_info()



The group number passed to ext4_get_group_info() should be valid, but
let's add an assert to check this before we start creating a pointer
based on that group number and dereferencing it.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent b302ef2d

fs/ext4/ext4.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -2313,6 +2313,7 @@ struct ext4_group_info ext4_get_group_info(struct super_block sb,
		{
		struct ext4_group_info ***grp_info;
		long indexv, indexh;
		BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
		grp_info = EXT4_SB(sb)->s_group_info;
		indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
		indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);