Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 014/118] hfsplus: prevent btree data loss on root split | Date | Mon, 26 Nov 2018 11:50:08 +0100 |
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4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 0a3021d4f5295aa073c7bf5c5e4de60a2e292578 ]
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 <ernesto.mnd.fernandez@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/hfsplus/brec.c | 4 ++++ 1 file changed, 4 insertions(+)
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); -- 2.17.1
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