The patch titled Subject: fs: hfsplus: fix UAF issue in hfsplus_put_super has been added to the -mm mm-hotfixes-unstable branch. Its filename is fs-hfsplus-fix-uaf-issue-in-hfsplus_put_super.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days

------------------------------------------------------ From: Dongliang Mu mudongliangabcd@gmail.com Subject: fs: hfsplus: fix UAF issue in hfsplus_put_super Date: Sun, 26 Feb 2023 20:49:47 +0800

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 mudongliangabcd@gmail.com Signed-off-by: Dongliang Mu mudongliangabcd@gmail.com Cc: Bart Van Assche bvanassche@acm.org Cc: Jens Axboe axboe@kernel.dk Cc: Muchun Song songmuchun@bytedance.com Cc: Roman Gushchin roman.gushchin@linux.dev Cc: "Theodore Ts'o" tytso@mit.edu Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

--- a/fs/hfsplus/super.c~fs-hfsplus-fix-uaf-issue-in-hfsplus_put_super +++ 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); _

Patches currently in -mm which might be from mudongliangabcd@gmail.com are

fs-hfsplus-fix-uaf-issue-in-hfsplus_put_super.patch