From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F236FC636D7 for ; Thu, 9 Feb 2023 11:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231279AbjBILYJ (ORCPT ); Thu, 9 Feb 2023 06:24:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231214AbjBILXV (ORCPT ); Thu, 9 Feb 2023 06:23:21 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 726B45C4A6; Thu, 9 Feb 2023 03:18:55 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C2F89619E8; Thu, 9 Feb 2023 11:18:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BF85C433D2; Thu, 9 Feb 2023 11:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675941504; bh=UjbjQ8Yer2dYefk720z6z+rFveRSZQ0hi4knrXkKSYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kYj3nlPEdpBag0m3QQ9fzBHm+Pf3kZcHXQrLfrOwx0/xtlUtVG+q/snXPNjCkBSwl WaShmhr6mgXGZge9sI/bdJysf+bBKwlsbAoTlFT0ejzr2lKbNbfNIuzQelULv4wyep rB73Q915jlJKgXna0kuWpDmYl2CppSssuXE67WPRJ9cV2IkFE4xgOidB19a4m9nuD1 Hfc2cuBxayyfkaV9+hz32y+tnlUG7pGMGzk5ykfxkFuc+LTVkG09bdwgUmDr9pEGcg un8B+Uiard6tC70sebbw42okR6NNwL0Thof4m9qKXjpXErPseTFV7ssdUd59AsPT5q EQzru5QrZ5skw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vasily Gorbik , Alexander Egorenkov , Heiko Carstens , Sasha Levin , agordeev@linux.ibm.com, terrelln@fb.com, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 14/17] s390/decompressor: specify __decompress() buf len to avoid overflow Date: Thu, 9 Feb 2023 06:17:26 -0500 Message-Id: <20230209111731.1892569-14-sashal@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230209111731.1892569-1-sashal@kernel.org> References: <20230209111731.1892569-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vasily Gorbik [ Upstream commit 7ab41c2c08a32132ba8c14624910e2fe8ce4ba4b ] Historically calls to __decompress() didn't specify "out_len" parameter on many architectures including s390, expecting that no writes beyond uncompressed kernel image are performed. This has changed since commit 2aa14b1ab2c4 ("zstd: import usptream v1.5.2") which includes zstd library commit 6a7ede3dfccb ("Reduce size of dctx by reutilizing dst buffer (#2751)"). Now zstd decompression code might store literal buffer in the unwritten portion of the destination buffer. Since "out_len" is not set, it is considered to be unlimited and hence free to use for optimization needs. On s390 this might corrupt initrd or ipl report which are often placed right after the decompressor buffer. Luckily the size of uncompressed kernel image is already known to the decompressor, so to avoid the problem simply specify it in the "out_len" parameter. Link: https://github.com/facebook/zstd/commit/6a7ede3dfccb Signed-off-by: Vasily Gorbik Tested-by: Alexander Egorenkov Link: https://lore.kernel.org/r/patch-1.thread-41c676.git-41c676c2d153.your-ad-here.call-01675030179-ext-9637@work.hours Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/boot/compressed/decompressor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/boot/compressed/decompressor.c b/arch/s390/boot/compressed/decompressor.c index e27c2140d6206..623f6775d01d7 100644 --- a/arch/s390/boot/compressed/decompressor.c +++ b/arch/s390/boot/compressed/decompressor.c @@ -80,6 +80,6 @@ void *decompress_kernel(void) void *output = (void *)decompress_offset; __decompress(_compressed_start, _compressed_end - _compressed_start, - NULL, NULL, output, 0, NULL, error); + NULL, NULL, output, vmlinux.image_size, NULL, error); return output; } -- 2.39.0