On Mon, Mar 23, 2020 at 03:43:02PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 236ebc20d9afc5e9ff52f3cf3f365a91583aac10 Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Tue, 10 Mar 2020 12:13:53 +0000
Subject: [PATCH] btrfs: fix log context list corruption after rename whiteout
error
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
we can end up returning from btrfs_rename() with the log context object
still in the root's log context list - this happens if 'sync_log' was
set to true before we called btrfs_whiteout_for_rename() and it is
dangerous because we end up with a corrupt linked list (root->log_ctxs)
as the log context object was allocated on the stack.
After btrfs_rename() returns, any task that is running btrfs_sync_log()
concurrently can end up crashing because that linked list is traversed by
btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list
corruption after rename exchange operation") fixed.
Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name")
CC: stable@xxxxxxxxxxxxxxx # 4.19+
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Greg, I'm not sure why you tried this for 4.14 - it's tagged 4.19+ and
we don't have d4682ba03ef618 in 4.14 either.
--
Thanks,
Sasha
