This is a note to let you know that I've just added the patch titled
ext4: check and assert if marking an no_delete evicting inode dirty
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-check-and-assert-if-marking-an-no_delete-evicting-inode-dirty.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 318cdc822c63b6e2befcfdc2088378ae6fa18def Mon Sep 17 00:00:00 2001
From: Zhang Yi <yi.zhang@xxxxxxxxxx>
Date: Wed, 29 Jun 2022 19:26:47 +0800
Subject: ext4: check and assert if marking an no_delete evicting inode dirty
From: Zhang Yi <yi.zhang@xxxxxxxxxx>
commit 318cdc822c63b6e2befcfdc2088378ae6fa18def upstream.
In ext4_evict_inode(), if we evicting an inode in the 'no_delete' path,
it cannot be raced by another mark_inode_dirty(). If it happens,
someone else may accidentally dirty it without holding inode refcount
and probably cause use-after-free issues in the writeback procedure.
It's indiscoverable and hard to debug, so add an WARN_ON_ONCE() to
check and detect this issue in advance.
Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20220629112647.4141034-2-yi.zhang@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -338,6 +338,12 @@ stop_handle:
ext4_xattr_inode_array_free(ea_inode_array);
return;
no_delete:
+ /*
+ * Check out some where else accidentally dirty the evicting inode,
+ * which may probably cause inode use-after-free issues later.
+ */
+ WARN_ON_ONCE(!list_empty_careful(&inode->i_io_list));
+
if (!list_empty(&EXT4_I(inode)->i_fc_list))
ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM, NULL);
ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
Patches currently in stable-queue which might be from yi.zhang@xxxxxxxxxx are
queue-5.15/ext4-check-and-assert-if-marking-an-no_delete-evicting-inode-dirty.patch
queue-5.15/ext4-silence-the-warning-when-evicting-inode-with-dioread_nolock.patch
