This is a note to let you know that I've just added the patch titled
btrfs: zlib: zero-initialize zlib workspace
to the 5.10-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-zlib-zero-initialize-zlib-workspace.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From eadd7deca0ad8a83edb2b894d8326c78e78635d6 Mon Sep 17 00:00:00 2001
From: Alexander Potapenko <glider@xxxxxxxxxx>
Date: Tue, 24 Jan 2023 12:32:34 +0100
Subject: btrfs: zlib: zero-initialize zlib workspace
From: Alexander Potapenko <glider@xxxxxxxxxx>
commit eadd7deca0ad8a83edb2b894d8326c78e78635d6 upstream.
KMSAN reports uses of uninitialized memory in zlib's longest_match()
called on memory originating from zlib_alloc_workspace().
This issue is known by zlib maintainers and is claimed to be harmless,
but to be on the safe side we'd better initialize the memory.
Link: https://zlib.net/zlib_faq.html#faq36
Reported-by: syzbot+14d9e7602ebdf7ec0a60@xxxxxxxxxxxxxxxxxxxxxxxxx
CC: stable@xxxxxxxxxxxxxxx # 5.4+
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/zlib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -63,7 +63,7 @@ struct list_head *zlib_alloc_workspace(u
workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
zlib_inflate_workspacesize());
- workspace->strm.workspace = kvmalloc(workspacesize, GFP_KERNEL);
+ workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL);
workspace->level = level;
workspace->buf = NULL;
/*
Patches currently in stable-queue which might be from glider@xxxxxxxxxx are
queue-5.10/btrfs-zlib-zero-initialize-zlib-workspace.patch
