From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by sourceware.org (Postfix) with ESMTPS id 5A6D238582BA for ; Thu, 16 Jun 2022 08:44:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 5A6D238582BA Received: by mail-pl1-x62e.google.com with SMTP id h1so740490plf.11 for ; Thu, 16 Jun 2022 01:44:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-disposition; bh=MHDW1GVNt+YcI18mEBETh8QTPhrXSmFoLqYPOCQYQWA=; b=kfvPJtqCs56ufooqfU/DfbVMO/BhFjqdAGDo5RYqY6Db5LiQi8qSDPiRWXxk5XR7xg 1gn/ZZIw97s7QW0xi3TzVTVZGHckq4VguNV57/bbKD6icHxT48sd5HVRU1SrJ6zKzvb8 Qh1HUzJ/FyrrTAr4gn11I83rzthSNMW+xWzVOB9hbD+jaK9M4T+2x+zxQ7HETLLuZVIJ AarIIh/0X8Mtnk7UPo3XkkmPqlmp1fSOFrXuVbDEC9Vuj9UW2v6h4bJob/h1w3wyHqg3 6PkJtM2bqjIA6YjdwjXwXszvzRea49m3VTQxkrvHREnnV5EkssXuZn1yMvWe0Tb2FxLZ b7Nw== X-Gm-Message-State: AJIora9GHv4U4HA4+hW8lDMrUTPsG8Lf2lOzfAxP4kbZ+PNkwnC+gymP 0bTRnYWqybTllpzyEs2yUMDkIFMKYAQ= X-Google-Smtp-Source: AGRyM1sY8+Rq673Qu3lXV3S/H1hngeGKezXyWz6oZI6r+L/r8UyQKgLt7D4gK+8XZSg4FqU1y3PAEQ== X-Received: by 2002:a17:90b:3909:b0:1e8:46ef:d64 with SMTP id ob9-20020a17090b390900b001e846ef0d64mr3868678pjb.90.1655369051062; Thu, 16 Jun 2022 01:44:11 -0700 (PDT) Received: from squeak.grove.modra.org (158.106.96.58.static.exetel.com.au. [58.96.106.158]) by smtp.gmail.com with ESMTPSA id ep2-20020a17090ae64200b001e2f3831102sm983786pjb.17.2022.06.16.01.44.10 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Jun 2022 01:44:10 -0700 (PDT) Received: by squeak.grove.modra.org (Postfix, from userid 1000) id BB8141143225; Thu, 16 Jun 2022 18:14:07 +0930 (ACST) Date: Thu, 16 Jun 2022 18:14:07 +0930 From: Alan Modra To: binutils@sourceware.org Subject: use of uninitialised value in input_file_open Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3037.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: binutils@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Binutils mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Jun 2022 08:44:13 -0000 Triggered by a file containing just "#N" or "#A". fgets when hitting EOF before reading anything returns NULL and does not write to buf. strchr (buf, '\n') then is reading from uninitialised memory. * input-file.c (input_file_open): Don't assume buf contains zero string terminator when fgets returns NULL. diff --git a/gas/input-file.c b/gas/input-file.c index f1085c1f0f1..d7cf56cc09a 100644 --- a/gas/input-file.c +++ b/gas/input-file.c @@ -170,20 +170,20 @@ input_file_open (const char *filename, c = getc (f_in); if (c == 'N') { - if (fgets (buf, sizeof (buf), f_in) - && startswith (buf, "O_APP") && ISSPACE (buf[5])) + char *p = fgets (buf, sizeof (buf), f_in); + if (p && startswith (p, "O_APP") && ISSPACE (p[5])) preprocess = 0; - if (!strchr (buf, '\n')) - ungetc ('#', f_in); /* It was longer. */ + if (!p || !strchr (p, '\n')) + ungetc ('#', f_in); else ungetc ('\n', f_in); } else if (c == 'A') { - if (fgets (buf, sizeof (buf), f_in) - && startswith (buf, "PP") && ISSPACE (buf[2])) + char *p = fgets (buf, sizeof (buf), f_in); + if (p && startswith (p, "PP") && ISSPACE (p[2])) preprocess = 1; - if (!strchr (buf, '\n')) + if (!p || !strchr (p, '\n')) ungetc ('#', f_in); else ungetc ('\n', f_in); -- Alan Modra Australia Development Lab, IBM