From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf41.google.com (mail-qv1-xf41.google.com [IPv6:2607:f8b0:4864:20::f41]) by sourceware.org (Postfix) with ESMTPS id 6536F3858D35 for ; Wed, 7 Oct 2020 18:10:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 6536F3858D35 Received: by mail-qv1-xf41.google.com with SMTP id b19so1694049qvm.6 for ; Wed, 07 Oct 2020 11:10:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:autocrypt:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=WYZJl3EdTE5Go4lgt/ADSMabrCfSuLA6zpR537UvOGs=; b=Rk0Fs3gfignsxNRd8J2JVeUTbwGvFvqgEXs/2N4+KqGgazROAq0M4NC4UL2q1OQXLI aCAU6UiFsOvVAlOA1W6AkaRVrrs3NI47+c4sXSOSqNvM8FBJyoI714PSRkxvdj9splJ8 lwMlsvge3FvNBJVOl7Ot802O3g97KyVqF0YLSohNKjQQdootsAc7F+b4JAQ8qPGMetz1 LXT58B4p8T2Z4Ti7cbeaS76A9FGzrBqwhFg5mPw3juk9z2BnRYVJYk4DyNjKhSbIqT57 d3BFMdjEWeXD9UuUgRPkMlNQhl4D3Xj4uzma0VFAUZarn8OIrxVXNsB9bM4NLGcJsPI7 hEqg== X-Gm-Message-State: AOAM533aUQVqlrdebhr1E+CJEkEQdBt7kYzasgvafbHM/3B0NBUAOHOj wr/MzzMacMJbUkP1A4Y0AZ5lsA== X-Google-Smtp-Source: ABdhPJx12rTJqRhgKdDm1smKgxAiBFOQCXqI8wiM4ig6CF+YBsj103FolmyDz+tum17cPm8P06+dDA== X-Received: by 2002:a0c:bd85:: with SMTP id n5mr4408726qvg.22.1602094226943; Wed, 07 Oct 2020 11:10:26 -0700 (PDT) Received: from [192.168.1.4] ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id d9sm2163548qtg.51.2020.10.07.11.10.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Oct 2020 11:10:26 -0700 (PDT) Subject: Re: [PATCH] Fix aliasing violation in __vfscanf_internal [BZ #26690] To: libc-alpha@sourceware.org, Florian Weimer , Szabolcs Nagy References: <20201007175049.32564-1-szabolcs.nagy@arm.com> <87lfgh52pm.fsf@mid.deneb.enyo.de> From: Adhemerval Zanella Autocrypt: addr=adhemerval.zanella@linaro.org; prefer-encrypt=mutual; keydata= mQINBFcVGkoBEADiQU2x/cBBmAVf5C2d1xgz6zCnlCefbqaflUBw4hB/bEME40QsrVzWZ5Nq 8kxkEczZzAOKkkvv4pRVLlLn/zDtFXhlcvQRJ3yFMGqzBjofucOrmdYkOGo0uCaoJKPT186L NWp53SACXguFJpnw4ODI64ziInzXQs/rUJqrFoVIlrPDmNv/LUv1OVPKz20ETjgfpg8MNwG6 iMizMefCl+RbtXbIEZ3TE/IaDT/jcOirjv96lBKrc/pAL0h/O71Kwbbp43fimW80GhjiaN2y WGByepnkAVP7FyNarhdDpJhoDmUk9yfwNuIuESaCQtfd3vgKKuo6grcKZ8bHy7IXX1XJj2X/ BgRVhVgMHAnDPFIkXtP+SiarkUaLjGzCz7XkUn4XAGDskBNfbizFqYUQCaL2FdbW3DeZqNIa nSzKAZK7Dm9+0VVSRZXP89w71Y7JUV56xL/PlOE+YKKFdEw+gQjQi0e+DZILAtFjJLoCrkEX w4LluMhYX/X8XP6/C3xW0yOZhvHYyn72sV4yJ1uyc/qz3OY32CRy+bwPzAMAkhdwcORA3JPb kPTlimhQqVgvca8m+MQ/JFZ6D+K7QPyvEv7bQ7M+IzFmTkOCwCJ3xqOD6GjX3aphk8Sr0dq3 4Awlf5xFDAG8dn8Uuutb7naGBd/fEv6t8dfkNyzj6yvc4jpVxwARAQABtElBZGhlbWVydmFs IFphbmVsbGEgTmV0dG8gKExpbmFybyBWUE4gS2V5KSA8YWRoZW1lcnZhbC56YW5lbGxhQGxp bmFyby5vcmc+iQI3BBMBCAAhBQJXFRpKAhsDBQsJCAcDBRUKCQgLBRYCAwEAAh4BAheAAAoJ EKqx7BSnlIjv0e8P/1YOYoNkvJ+AJcNUaM5a2SA9oAKjSJ/M/EN4Id5Ow41ZJS4lUA0apSXW NjQg3VeVc2RiHab2LIB4MxdJhaWTuzfLkYnBeoy4u6njYcaoSwf3g9dSsvsl3mhtuzm6aXFH /Qsauav77enJh99tI4T+58rp0EuLhDsQbnBic/ukYNv7sQV8dy9KxA54yLnYUFqH6pfH8Lly sTVAMyi5Fg5O5/hVV+Z0Kpr+ZocC1YFJkTsNLAW5EIYSP9ftniqaVsim7MNmodv/zqK0IyDB GLLH1kjhvb5+6ySGlWbMTomt/or/uvMgulz0bRS+LUyOmlfXDdT+t38VPKBBVwFMarNuREU2 69M3a3jdTfScboDd2ck1u7l+QbaGoHZQ8ZNUrzgObltjohiIsazqkgYDQzXIMrD9H19E+8fw kCNUlXxjEgH/Kg8DlpoYJXSJCX0fjMWfXywL6ZXc2xyG/hbl5hvsLNmqDpLpc1CfKcA0BkK+ k8R57fr91mTCppSwwKJYO9T+8J+o4ho/CJnK/jBy1pWKMYJPvvrpdBCWq3MfzVpXYdahRKHI ypk8m4QlRlbOXWJ3TDd/SKNfSSrWgwRSg7XCjSlR7PNzNFXTULLB34sZhjrN6Q8NQZsZnMNs TX8nlGOVrKolnQPjKCLwCyu8PhllU8OwbSMKskcD1PSkG6h3r0AquQINBFcVGkoBEACgAdbR Ck+fsfOVwT8zowMiL3l9a2DP3Eeak23ifdZG+8Avb/SImpv0UMSbRfnw/N81IWwlbjkjbGTu oT37iZHLRwYUFmA8fZX0wNDNKQUUTjN6XalJmvhdz9l71H3WnE0wneEM5ahu5V1L1utUWTyh VUwzX1lwJeV3vyrNgI1kYOaeuNVvq7npNR6t6XxEpqPsNc6O77I12XELic2+36YibyqlTJIQ V1SZEbIy26AbC2zH9WqaKyGyQnr/IPbTJ2Lv0dM3RaXoVf+CeK7gB2B+w1hZummD21c1Laua +VIMPCUQ+EM8W9EtX+0iJXxI+wsztLT6vltQcm+5Q7tY+HFUucizJkAOAz98YFucwKefbkTp eKvCfCwiM1bGatZEFFKIlvJ2QNMQNiUrqJBlW9nZp/k7pbG3oStOjvawD9ZbP9e0fnlWJIsj 6c7pX354Yi7kxIk/6gREidHLLqEb/otuwt1aoMPg97iUgDV5mlNef77lWE8vxmlY0FBWIXuZ yv0XYxf1WF6dRizwFFbxvUZzIJp3spAao7jLsQj1DbD2s5+S1BW09A0mI/1DjB6EhNN+4bDB SJCOv/ReK3tFJXuj/HbyDrOdoMt8aIFbe7YFLEExHpSk+HgN05Lg5TyTro8oW7TSMTk+8a5M kzaH4UGXTTBDP/g5cfL3RFPl79ubXwARAQABiQIfBBgBCAAJBQJXFRpKAhsMAAoJEKqx7BSn lIjvI/8P/jg0jl4Tbvg3B5kT6PxJOXHYu9OoyaHLcay6Cd+ZrOd1VQQCbOcgLFbf4Yr+rE9l mYsY67AUgq2QKmVVbn9pjvGsEaz8UmfDnz5epUhDxC6yRRvY4hreMXZhPZ1pbMa6A0a/WOSt AgFj5V6Z4dXGTM/lNManr0HjXxbUYv2WfbNt3/07Db9T+GZkpUotC6iknsTA4rJi6u2ls0W9 1UIvW4o01vb4nZRCj4rni0g6eWoQCGoVDk/xFfy7ZliR5B+3Z3EWRJcQskip/QAHjbLa3pml xAZ484fVxgeESOoaeC9TiBIp0NfH8akWOI0HpBCiBD5xaCTvR7ujUWMvhsX2n881r/hNlR9g fcE6q00qHSPAEgGr1bnFv74/1vbKtjeXLCcRKk3Ulw0bY1OoDxWQr86T2fZGJ/HIZuVVBf3+ gaYJF92GXFynHnea14nFFuFgOni0Mi1zDxYH/8yGGBXvo14KWd8JOW0NJPaCDFJkdS5hu0VY 7vJwKcyHJGxsCLU+Et0mryX8qZwqibJIzu7kUJQdQDljbRPDFd/xmGUFCQiQAncSilYOcxNU EMVCXPAQTteqkvA+gNqSaK1NM9tY0eQ4iJpo+aoX8HAcn4sZzt2pfUB9vQMTBJ2d4+m/qO6+ cFTAceXmIoFsN8+gFN3i8Is3u12u8xGudcBPvpoy4OoG Message-ID: <6a8269f0-e514-22e4-d64e-b93986298577@linaro.org> Date: Wed, 7 Oct 2020 15:10:24 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <87lfgh52pm.fsf@mid.deneb.enyo.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-13.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Oct 2020 18:10:28 -0000 On 07/10/2020 15:08, Florian Weimer wrote: > * Szabolcs Nagy via Libc-alpha: > >> diff --git a/stdio-common/vfscanf-internal.c b/stdio-common/vfscanf-internal.c >> index 95b46dcbeb..d832493623 100644 >> --- a/stdio-common/vfscanf-internal.c >> +++ b/stdio-common/vfscanf-internal.c >> @@ -135,6 +135,16 @@ >> >> #include "printf-parse.h" /* Use read_int. */ >> >> +/* Same as read_int, but for CHAR_T * instead of UCHAR_T * string. */ >> +static int >> +read_int_char (const CHAR_T * *pstr) >> +{ >> + const UCHAR_T *ustr = (const UCHAR_T *) *pstr; >> + int retval = read_int (&ustr); >> + *pstr = (const CHAR_T *) ustr; >> + return retval; >> +} >> + >> #define encode_error() do { \ >> __set_errno (EILSEQ); \ >> goto errout; \ >> @@ -486,7 +496,7 @@ __vfscanf_internal (FILE *s, const char *format, va_list argptr, >> /* Check for a positional parameter specification. */ >> if (ISDIGIT ((UCHAR_T) *f)) >> { >> - argpos = read_int ((const UCHAR_T **) &f); >> + argpos = read_int_char (&f); >> if (*f == L_('$')) >> ++f; >> else >> @@ -522,7 +532,7 @@ __vfscanf_internal (FILE *s, const char *format, va_list argptr, >> /* Find the maximum field width. */ >> width = 0; >> if (ISDIGIT ((UCHAR_T) *f)) >> - width = read_int ((const UCHAR_T **) &f); >> + width = read_int_char (&f); >> got_width: >> if (width == 0) >> width = -1; > > Patch and commit message look reasonable to me. Thanks. > Andreas has sent a similar fix for the same issue [1]. Is it something wrong with his fix? It seems to cover more aliasing violation [1] https://sourceware.org/pipermail/libc-alpha/2020-October/118149.html