diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 790db7eac6c2..08d15cd2b594 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2000,8 +2000,17 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, else split = count/2; + if (WARN_ON_ONCE(split == 0)) { + /* Should never happen, but avoid out-of-bounds access below */ + ext4_error_inode_block(dir, (*bh)->b_blocknr, 0, + "bad indexed directory? hash=%08x:%08x count=%d move=%u", + hinfo->hash, hinfo->minor_hash, count, move); + err = -EFSCORRUPTED; + goto out; + } + hash2 = map[split].hash; - continued = split > 0 ? hash2 == map[split - 1].hash : 0; + continued = hash2 == map[split - 1].hash; dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", (unsigned long)dx_get_block(frame->at), hash2, split, count-split)); @@ -2043,10 +2052,11 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, return de; journal_error: + ext4_std_error(dir->i_sb, err); +out: brelse(*bh); brelse(bh2); *bh = NULL; - ext4_std_error(dir->i_sb, err); return ERR_PTR(err); }