Commit eadd7dec authored by Alexander Potapenko's avatar Alexander Potapenko Committed by David Sterba
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btrfs: zlib: zero-initialize zlib workspace 

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: default avatar <syzbot+14d9e7602ebdf7ec0a60@syzkaller.appspotmail.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: default avatarAlexander Potapenko <glider@google.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3c538de0

fs/btrfs/zlib.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -63,7 +63,7 @@ struct list_head *zlib_alloc_workspace(unsigned int level) 




	workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),

	workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),

			zlib_inflate_workspacesize());

			zlib_inflate_workspacesize());

	workspace->strm.workspace = kvmalloc(workspacesize, GFP_KERNEL);

	workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL);

	workspace->level = level;

	workspace->level = level;

	workspace->buf = NULL;

	workspace->buf = NULL;

	/*

	/*