From patchwork Fri Jun 30 11:04:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: yguoaz X-Patchwork-Id: 13298034 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 65328EB64DA for ; Fri, 30 Jun 2023 11:05:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232663AbjF3LFi (ORCPT ); Fri, 30 Jun 2023 07:05:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232900AbjF3LFC (ORCPT ); Fri, 30 Jun 2023 07:05:02 -0400 Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9497A3C23 for ; Fri, 30 Jun 2023 04:04:30 -0700 (PDT) Received: by mail-qk1-x72c.google.com with SMTP id af79cd13be357-76243a787a7so169677585a.2 for ; Fri, 30 Jun 2023 04:04:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1688123069; x=1690715069; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=nNa2jhHKlTe8HWrkGdDm3aUlIAQe4cmAyfQyFrrhTfc=; b=kGYQRxBov2CyhQNstEIg5lLvZbNwsSf1gnQYnGQmK2nccjDLe8tf7oVi3OXESw9lL9 K9v81fuu4rNIyiob2dbi0vKY6Fy4wmGgad22z6HAP4lA0PrCiy4Wr8Nf3fx9yxkuQhj4 vJXKLQ96u9OMwfHofK4RqhLrXcc3iHBU3s0utbeW3mYDl34D2Oumw0ipBCm3pDw43VA5 /FAa7q1cqNjKyu04TNNDfnJ96Y7GKHrC61c3ydzQP94AUeMkzDmftAJTCqdOIC2c/kab jc1wGQkx1uy26d2oHmU6MGEacCUD5Pf9b7VcUPMnFCNojmoynM6NfIeTw+gUfPVZpqS0 6gRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688123069; x=1690715069; 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=nNa2jhHKlTe8HWrkGdDm3aUlIAQe4cmAyfQyFrrhTfc=; b=QAW8ADAbQIDDuNHeORnfMyQ/kTLkGA+RvHx7G4ZV0a/vsm84URQAhNm50c7coYfttF uIx9/o18lCUYYzChRByn6ghfmkP13lmAsucHEcq9ug+mEGxKqVIqLBuAQdsoxFWnxAIL ilLfSHE2+LXXhN2o4fFkG6V+BG/5xS74x4fjRbMAdkghMdJp5XBCF9VXLlP6UwZ0GBJ8 VniofJXhLZM7BDm3T5D6jTr0vCK6fj8b3Trk18QkczGJ5IM184NUNzqmPR2ZWeV+MuCK GldPgnFFjkPis08xB7X93C/EbC2N0k4g8o3m/D7jD7dnYKT0n7uE9Og/fMpkh0zoAAdX XBhA== X-Gm-Message-State: ABy/qLZrwhX7U62qwoShlmLV//wC7T/4Dj9G7BJhBN3CwQUjzV8ts4JN Ll9sQ9gr+94fTr9KbOO4nrI= X-Google-Smtp-Source: APBJJlEUd/C+Gqe5xbab+Mp8OTZKfGeZ/gmXam2lRfmhAN8dHCH2+9aRPVqihHCbCEis/ZWYaaCMCg== X-Received: by 2002:a05:6214:29ee:b0:630:6926:d00e with SMTP id jv14-20020a05621429ee00b006306926d00emr2789055qvb.39.1688123069637; Fri, 30 Jun 2023 04:04:29 -0700 (PDT) Received: from chcpu17.cse.ust.hk (fc3kcs10.cse.ust.hk. [143.89.191.124]) by smtp.googlemail.com with ESMTPSA id m6-20020a0c9d06000000b0063659410b04sm435711qvf.107.2023.06.30.04.04.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Jun 2023 04:04:29 -0700 (PDT) From: Yiyuan Guo To: gregkh@linuxfoundation.org, dan.scally@ideasonboard.com, andriy.shevchenko@linux.intel.com Cc: frank.li@nxp.com, christophe.jaillet@wanadoo.fr, jgilab@gmail.com, chanh@os.amperecomputing.com, linux-usb@vger.kernel.org, yguoaz@gmail.com Subject: [PATCH] usb: gadget: configfs: Prevent buffer overrun in usb_string_copy Date: Fri, 30 Jun 2023 19:04:01 +0800 Message-Id: <20230630110401.2360746-1-yguoaz@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In usb_string_copy(), when `strlen(s) == 0`, `str[ret - 1]` accesses at index -1. Add a check to prevent buffer overrun when `s` is empty. Signed-off-by: Yiyuan Guo --- drivers/usb/gadget/configfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index 4c639e9ddedc..457dbc267964 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -127,7 +127,7 @@ static int usb_string_copy(const char *s, char **s_copy) return -ENOMEM; } strcpy(str, s); - if (str[ret - 1] == '\n') + if (ret && str[ret - 1] == '\n') str[ret - 1] = '\0'; *s_copy = str; return 0;