This is a note to let you know that I've just added the patch titled
btrfs: fix extent map use-after-free when handling missing device in read_one_chunk
to the 6.0-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:
btrfs-fix-extent-map-use-after-free-when-handling-missing-device-in-read_one_chunk.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1742e1c90c3da344f3bb9b1f1309b3f47482756a Mon Sep 17 00:00:00 2001
From: void0red <void0red@xxxxxxxxx>
Date: Wed, 23 Nov 2022 22:39:45 +0800
Subject: btrfs: fix extent map use-after-free when handling missing device in read_one_chunk
From: void0red <void0red@xxxxxxxxx>
commit 1742e1c90c3da344f3bb9b1f1309b3f47482756a upstream.
Store the error code before freeing the extent_map. Though it's
reference counted structure, in that function it's the first and last
allocation so this would lead to a potential use-after-free.
The error can happen eg. when chunk is stored on a missing device and
the degraded mount option is missing.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216721
Reported-by: eriri <1527030098@xxxxxx>
Fixes: adfb69af7d8c ("btrfs: add_missing_dev() should return the actual error")
CC: stable@xxxxxxxxxxxxxxx # 4.9+
Signed-off-by: void0red <void0red@xxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/volumes.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7128,8 +7128,9 @@ static int read_one_chunk(struct btrfs_k
map->stripes[i].dev = handle_missing_device(fs_info,
devid, uuid);
if (IS_ERR(map->stripes[i].dev)) {
+ ret = PTR_ERR(map->stripes[i].dev);
free_extent_map(em);
- return PTR_ERR(map->stripes[i].dev);
+ return ret;
}
}
Patches currently in stable-queue which might be from void0red@xxxxxxxxx are
queue-6.0/btrfs-fix-extent-map-use-after-free-when-handling-missing-device-in-read_one_chunk.patch
