From 0a3021d4f5295aa073c7bf5c5e4de60a2e292578 Mon Sep 17 00:00:00 2001 From: "Ernesto A. Fernández" Date: Tue, 30 Oct 2018 15:06:00 -0700 Subject: hfsplus: prevent btree data loss on root split MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Creating, renaming or deleting a file may cause catalog corruption and data loss. This bug is randomly triggered by xfstests generic/027, but here is a faster reproducer: truncate -s 50M fs.iso mkfs.hfsplus fs.iso mount fs.iso /mnt i=100 while [ $i -le 150 ]; do touch /mnt/$i &>/dev/null ((++i)) done i=100 while [ $i -le 150 ]; do mv /mnt/$i /mnt/$(perl -e "print $i x82") &>/dev/null ((++i)) done umount /mnt fsck.hfsplus -n fs.iso The bug is triggered whenever hfs_brec_update_parent() needs to split the root node. The height of the btree is not increased, which leaves the new node orphaned and its records lost. Link: http://lkml.kernel.org/r/26d882184fc43043a810114258f45277752186c7.1535682461.git.ernesto.mnd.fernandez@gmail.com Signed-off-by: Ernesto A. Fernández Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hfsplus/brec.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/hfsplus') diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c index ed8eacb34452..aa17a392b414 100644 --- a/fs/hfsplus/brec.c +++ b/fs/hfsplus/brec.c @@ -429,6 +429,10 @@ skip: if (new_node) { __be32 cnid; + if (!new_node->parent) { + hfs_btree_inc_height(tree); + new_node->parent = tree->root; + } fd->bnode = hfs_bnode_find(tree, new_node->parent); /* create index key and entry */ hfs_bnode_read_key(new_node, fd->search_key, 14); -- cgit v1.2.3