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/fs-hfsplus-fix-uaf-issue-in-hfsplus_put_super.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
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@xxxxxxxxx
Reported-by: syzbot+57e3e98f7e3b80f64d56@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- 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@xxxxxxxxx are
fs-hfsplus-fix-uaf-issue-in-hfsplus_put_super.patch
