From: Baokun Li Date: Thu, 4 Jan 2024 14:20:37 +0000 (+0800) Subject: ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt X-Git-Tag: v6.8-rc3~1^2~18 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=993bf0f4c393b3667830918f9247438a8f6fdb5b;p=thirdparty%2Fkernel%2Flinux.git ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt Determine if bb_fragments is 0 instead of determining bb_free to eliminate the risk of dividing by zero when the block bitmap is corrupted. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240104142040.2835097-6-libaokun1@huawei.com Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index fa351aa323dcf..751e31df0f104 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -842,7 +842,7 @@ mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) struct ext4_sb_info *sbi = EXT4_SB(sb); int new_order; - if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0) + if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0) return; new_order = mb_avg_fragment_size_order(sb,