Commit e45ab2d6 authored by Jan Kara's avatar Jan Kara Committed by Greg Kroah-Hartman

ext4: fix fencepost error in check for inode count overflow during resize

commit 4f2f76f751433908364ccff82f437a57d0e6e9b7 upstream.

ext4_resize_fs() has an off-by-one bug when checking whether growing of
a filesystem will not overflow inode count. As a result it allows a
filesystem with 8192 inodes per group to grow to 64TB which overflows
inode count to 0 and makes filesystem unusable. Fix it.

Fixes: 3f8a6411Reported-by: default avatarJaco Kroon <>
Signed-off-by: default avatarJan Kara <>
Signed-off-by: default avatarTheodore Ts'o <>
Reviewed-by: default avatarAndreas Dilger <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent ade6e140
......@@ -1903,7 +1903,7 @@ retry:
return 0;
n_group = ext4_get_group_number(sb, n_blocks_count - 1);
if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
ext4_warning(sb, "resize would cause inodes_count overflow");
return -EINVAL;
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