From: Tristan Madani hfsplus_create_attributes_file() calls hfsplus_mark_inode_dirty() with HFSPLUS_ATTR_TREE_I(sb) before sbi->attr_tree has been set by hfs_btree_open(). HFSPLUS_ATTR_TREE_I dereferences sbi->attr_tree to reach ->inode, causing a null pointer dereference when attr_tree is still NULL. Move the mark_dirty call to after hfs_btree_open() and guard it with a NULL check on sbi->attr_tree. Reported-by: syzbot+bc70a12e438dadba4fb4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=bc70a12e438dadba4fb4 Tested-by: syzbot+bc70a12e438dadba4fb4@syzkaller.appspotmail.com Fixes: ee8422d00b7c ("hfsplus: fix potential Allocation File corruption after fsync") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani --- fs/hfsplus/xattr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c index 452a1f9becb2d..1ea9f313368c5 100644 --- a/fs/hfsplus/xattr.c +++ b/fs/hfsplus/xattr.c @@ -317,12 +317,13 @@ static int hfsplus_create_attributes_file(struct super_block *sb) next_node++; } - hfsplus_mark_inode_dirty(HFSPLUS_ATTR_TREE_I(sb), HFSPLUS_I_ATTR_DIRTY); hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY); sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID); if (!sbi->attr_tree) pr_err("failed to load attributes file\n"); + else + hfsplus_mark_inode_dirty(HFSPLUS_ATTR_TREE_I(sb), HFSPLUS_I_ATTR_DIRTY); failed_header_node_init: kfree(buf); -- 2.47.3