From nobody Tue Sep 16 14:11:50 2025 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 EBFA9C53210 for ; Tue, 3 Jan 2023 03:01:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232964AbjACDB3 (ORCPT ); Mon, 2 Jan 2023 22:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230071AbjACDB0 (ORCPT ); Mon, 2 Jan 2023 22:01:26 -0500 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FC33260F for ; Mon, 2 Jan 2023 19:01:25 -0800 (PST) Received: by mail-pl1-x62e.google.com with SMTP id y19so12209216plb.2 for ; Mon, 02 Jan 2023 19:01:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=quBw/ujluJ3rNnNfMKVBDJsfvvRIe1fyf1oyveqm1OY=; b=cw0B54keqMMjfjxXPvdfSKFtAdV/6qIqyYsFyMs4XcQgoJ2uSMZCmgxe0U6eaGD4RD J3v4V6eSIrgzEmSWmGPnzo97IafNF2fuEa0ZqyaiKtLF4hHd7pkHa24bsEdPoI7iVSXb +SsWCPw0kOUCmARlNVq9CwkAXgL41NlRhFt5M= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=quBw/ujluJ3rNnNfMKVBDJsfvvRIe1fyf1oyveqm1OY=; b=S2/be+G6hLQjnscE5EmEKT+qh/lmxHaUDIILGYE7G3BuSsKgG4DvamkLQzBbDsvmdk h8j0djWAHj8CVOUFdhai+fxq7tM5ioq2EoIP+nbXf0MTJGbsRx5rfgLipmxpN2OTHhzo zH24sLHSWqXNovHyj6HD3gwezUR5HWp7D19V2vYbyeU2GkU6P6X+TiimU69Ge6bv2g10 MRG9B7SVFIhZzaOqtehs1mLQyeIkaEnJOwntq4S9RC/ArEG5ZegAQsES33udqAbHZVS4 UUZG2eYDcH9g/ZY5xuCnkwFR+3ZEBnNj9NTwIallgNiXq65cBGwQlPzvUUZPvuHf3WQY bGow== X-Gm-Message-State: AFqh2kr9yS8zd8N5NjQiJ0eO63tKl3jbg8/rdOC2JqPlkpCZG2H222rp LhCbGwmWB06qpprrjL8prf0uQw== X-Google-Smtp-Source: AMrXdXt935vls5I/dh5pfohSB68qQnrMTZKGec2ZB29xqw7PU84GxyU26mWB1gff7duNesjBIZ4rQg== X-Received: by 2002:a17:902:ecc1:b0:192:760f:c35e with SMTP id a1-20020a170902ecc100b00192760fc35emr40224986plh.53.1672714885008; Mon, 02 Jan 2023 19:01:25 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:270a:35ec:5bc4:b90a]) by smtp.gmail.com with ESMTPSA id r10-20020a170902c60a00b001869b988d93sm20838638plr.187.2023.01.02.19.01.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Jan 2023 19:01:24 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCH] zram: correctly handle all next_arg() cases Date: Tue, 3 Jan 2023 12:01:19 +0900 Message-Id: <20230103030119.1496358-1-senozhatsky@chromium.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When supplied buffer does not have assignment sign next_arg() sets `val` pointer to NULL, so we cannot dereference it. Add a NULL pointer test to handle `param` case, in addition to `*val` test, which handles cases when param has no value assigned to it: `param=3D`. Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index e290d6d97047..70c412eb6c1f 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1140,7 +1140,7 @@ static ssize_t recomp_algorithm_store(struct device *= dev, while (*args) { args =3D next_arg(args, ¶m, &val); =20 - if (!*val) + if (!val || !*val) return -EINVAL; =20 if (!strcmp(param, "algo")) { @@ -1824,7 +1824,7 @@ static ssize_t recompress_store(struct device *dev, while (*args) { args =3D next_arg(args, ¶m, &val); =20 - if (!*val) + if (!val || !*val) return -EINVAL; =20 if (!strcmp(param, "type")) { --=20 2.39.0.314.g84b9a713c41-goog