From: Josef Bacik <josef@toxicpanda.com>
To: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH 09/13] btrfs: modify the new_root highest_objectid under a ref count
Date: Wed, 16 Dec 2020 11:22:13 -0500 [thread overview]
Message-ID: <db3b68c826ae28684100195170a913b13a23b567.1608135557.git.josef@toxicpanda.com> (raw)
In-Reply-To: <cover.1608135557.git.josef@toxicpanda.com>
Qu pointed out a bug in one of my error handling patches, which made me
notice that we modify the new_root->highest_objectid _after_ we've
dropped the ref to the new_root. This could lead to a possible UAF, fix
this by modifying the ->highest_objectid before we drop our reference to
the new_root.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/ioctl.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index dde49a791f3e..af8d01659562 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -717,6 +717,12 @@ static noinline int create_subvol(struct inode *dir,
btrfs_record_root_in_trans(trans, new_root);
ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
+ if (!ret) {
+ mutex_lock(&new_root->objectid_mutex);
+ new_root->highest_objectid = new_dirid;
+ mutex_unlock(&new_root->objectid_mutex);
+ }
+
btrfs_put_root(new_root);
if (ret) {
/* We potentially lose an unused inode item here */
@@ -724,10 +730,6 @@ static noinline int create_subvol(struct inode *dir,
goto fail;
}
- mutex_lock(&new_root->objectid_mutex);
- new_root->highest_objectid = new_dirid;
- mutex_unlock(&new_root->objectid_mutex);
-
/*
* insert the directory item
*/
--
2.26.2
next prev parent reply other threads:[~2020-12-16 16:23 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-16 16:22 [PATCH 00/13] Serious fixes for different error paths Josef Bacik
2020-12-16 16:22 ` [PATCH 01/13] btrfs: don't get an EINTR during drop_snapshot for reloc Josef Bacik
2021-01-11 21:56 ` David Sterba
2020-12-16 16:22 ` [PATCH 02/13] btrfs: initialize test inodes location Josef Bacik
2020-12-18 10:30 ` Nikolay Borisov
2020-12-21 16:58 ` David Sterba
2020-12-16 16:22 ` [PATCH 03/13] btrfs: fix reloc root leak with 0 ref reloc roots on recovery Josef Bacik
2020-12-16 16:22 ` [PATCH 04/13] btrfs: splice remaining dirty_bg's onto the transaction dirty bg list Josef Bacik
2021-01-11 22:09 ` David Sterba
2020-12-16 16:22 ` [PATCH 05/13] btrfs: do not WARN_ON() if we can't find the reloc root Josef Bacik
2021-01-11 22:14 ` David Sterba
2020-12-16 16:22 ` [PATCH 06/13] btrfs: add ASSERT()'s for deleting backref cache nodes Josef Bacik
2021-01-11 22:18 ` David Sterba
2020-12-16 16:22 ` [PATCH 07/13] btrfs: do not double free backref nodes on error Josef Bacik
2020-12-16 16:22 ` [PATCH 08/13] btrfs: abort the transaction if we fail to inc ref in btrfs_copy_root Josef Bacik
2021-01-11 22:20 ` David Sterba
2020-12-16 16:22 ` Josef Bacik [this message]
2020-12-18 11:18 ` [PATCH 09/13] btrfs: modify the new_root highest_objectid under a ref count Nikolay Borisov
2020-12-16 16:22 ` [PATCH 10/13] btrfs: fix lockdep splat in btrfs_recover_relocation Josef Bacik
2020-12-16 16:22 ` [PATCH 11/13] btrfs: keep track of the root owner for relocation reads Josef Bacik
2021-01-11 22:23 ` David Sterba
2021-01-14 18:03 ` David Sterba
2020-12-16 16:22 ` [PATCH 12/13] btrfs: do not cleanup upper nodes in btrfs_backref_cleanup_node Josef Bacik
2020-12-16 16:22 ` [PATCH 13/13] btrfs: don't clear ret in btrfs_start_dirty_block_groups Josef Bacik
2021-01-08 16:44 ` [PATCH 00/13] Serious fixes for different error paths David Sterba
2021-01-14 18:20 ` David Sterba
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