From 07db5e247ab5858439b14dd7cc1fe538b9efcf32 Mon Sep 17 00:00:00 2001 From: Dongliang Mu Date: Sun, 26 Feb 2023 20:49:47 +0800 Subject: [PATCH] fs: hfsplus: fix UAF issue in hfsplus_put_super The current hfsplus_put_super first calls hfs_btree_close on sbi->ext_tree, then invokes iput on sbi->hidden_dir, resulting in an use-after-free issue in hfsplus_release_folio. As shown in hfsplus_fill_super, the error handling code also calls iput before hfs_btree_close. To fix this error, we move all iput calls before hfsplus_btree_close. Note that this patch is tested on Syzbot. Link: https://lkml.kernel.org/r/20230226124948.3175736-1-mudongliangabcd@gmail.com Reported-by: syzbot+57e3e98f7e3b80f64d56@syzkaller.appspotmail.com Tested-by: Dongliang Mu Signed-off-by: Dongliang Mu Cc: Bart Van Assche Cc: Jens Axboe Cc: Muchun Song Cc: Roman Gushchin Cc: "Theodore Ts'o" Cc: Signed-off-by: Andrew Morton --- fs/hfsplus/super.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c index 122ed89ebf9f..1986b4f18a90 100644 --- a/fs/hfsplus/super.c +++ b/fs/hfsplus/super.c @@ -295,11 +295,11 @@ static void hfsplus_put_super(struct super_block *sb) hfsplus_sync_fs(sb, 1); } + iput(sbi->alloc_file); + iput(sbi->hidden_dir); hfs_btree_close(sbi->attr_tree); hfs_btree_close(sbi->cat_tree); hfs_btree_close(sbi->ext_tree); - iput(sbi->alloc_file); - iput(sbi->hidden_dir); kfree(sbi->s_vhdr_buf); kfree(sbi->s_backup_vhdr_buf); unload_nls(sbi->nls);