From patchwork Fri Jan 18 20:12:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 31115 Received: (qmail 91776 invoked by alias); 18 Jan 2019 20:12:50 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 91643 invoked by uid 89); 18 Jan 2019 20:12:49 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.2 required=5.0 tests=BAYES_00, FREEMAIL_FROM, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, SPF_SOFTFAIL autolearn=ham version=3.3.2 spammy=__ilp32__, __ILP32__, exhaustion, resource X-HELO: mga06.intel.com From: "H.J. Lu" To: libc-alpha@sourceware.org Subject: [PATCH 1/8] x86-64 memchr/wmemchr: Properly handle the length parameter [BZ# 24097] Date: Fri, 18 Jan 2019 12:12:30 -0800 Message-Id: <20190118201237.6729-2-hjl.tools@gmail.com> In-Reply-To: <20190118201237.6729-1-hjl.tools@gmail.com> References: <20190118201237.6729-1-hjl.tools@gmail.com> MIME-Version: 1.0 On x32, the size_t parameter may be passed in the lower 32 bits of a 64-bit register with the non-zero upper 32 bits. The string/memory functions written in assembly can only use the lower 32 bits of a 64-bit register as length or must clear the upper 32 bits before using the full 64-bit register for length. This pach fixes memchr/wmemchr for x32. Tested on x86-64 and x32. On x86-64, libc.so is the same with and withou the fix. [BZ# 24097] CVE-2019-6488 * sysdeps/x86_64/memchr.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memchr-avx2.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memchr and tst-size_t-wmemchr. * sysdeps/x86_64/x32/test-size_t.h: New file. * sysdeps/x86_64/x32/tst-size_t-memchr.c: Likewise. * sysdeps/x86_64/x32/tst-size_t-wmemchr.c: Likewise. --- NEWS | 6 +++ sysdeps/x86_64/memchr.S | 10 ++-- sysdeps/x86_64/multiarch/memchr-avx2.S | 8 ++- sysdeps/x86_64/x32/Makefile | 8 +++ sysdeps/x86_64/x32/test-size_t.h | 35 ++++++++++++ sysdeps/x86_64/x32/tst-size_t-memchr.c | 72 +++++++++++++++++++++++++ sysdeps/x86_64/x32/tst-size_t-wmemchr.c | 20 +++++++ 7 files changed, 154 insertions(+), 5 deletions(-) create mode 100644 sysdeps/x86_64/x32/test-size_t.h create mode 100644 sysdeps/x86_64/x32/tst-size_t-memchr.c create mode 100644 sysdeps/x86_64/x32/tst-size_t-wmemchr.c diff --git a/NEWS b/NEWS index cc20102fda..2885c42aa5 100644 --- a/NEWS +++ b/NEWS @@ -101,6 +101,12 @@ Security related changes: denial of service due to resource exhaustion when processing getaddrinfo calls with crafted host names. Reported by Guido Vranken. + CVE-2019-6488: On x32, the size_t parameter may be passed in the lower + 32 bits of a 64-bit register with the non-zero upper 32 bits. When + it happens, the string/memory functions written in assembly will cause + buffer overflow if the full 64-bit register is used as the 32-bit + size_t value. Reported by Florian Weimer. + The following bugs are resolved with this release: [The release manager will add the list generated by diff --git a/sysdeps/x86_64/memchr.S b/sysdeps/x86_64/memchr.S index a6f3ebba22..ec96365217 100644 --- a/sysdeps/x86_64/memchr.S +++ b/sysdeps/x86_64/memchr.S @@ -34,12 +34,16 @@ ENTRY(MEMCHR) mov %edi, %ecx #ifdef USE_AS_WMEMCHR - test %rdx, %rdx + test %RDX_LP, %RDX_LP jz L(return_null) - shl $2, %rdx + shl $2, %RDX_LP #else +# ifdef __ILP32__ + /* Clear the upper 32 bits. */ + movl %edx, %edx +# endif punpcklbw %xmm1, %xmm1 - test %rdx, %rdx + test %RDX_LP, %RDX_LP jz L(return_null) punpcklbw %xmm1, %xmm1 #endif diff --git a/sysdeps/x86_64/multiarch/memchr-avx2.S b/sysdeps/x86_64/multiarch/memchr-avx2.S index 9f98b7ec60..cfec1657b6 100644 --- a/sysdeps/x86_64/multiarch/memchr-avx2.S +++ b/sysdeps/x86_64/multiarch/memchr-avx2.S @@ -40,16 +40,20 @@ ENTRY (MEMCHR) # ifndef USE_AS_RAWMEMCHR /* Check for zero length. */ - testq %rdx, %rdx + test %RDX_LP, %RDX_LP jz L(null) # endif movl %edi, %ecx /* Broadcast CHAR to YMM0. */ vmovd %esi, %xmm0 # ifdef USE_AS_WMEMCHR - shl $2, %rdx + shl $2, %RDX_LP vpbroadcastd %xmm0, %ymm0 # else +# ifdef __ILP32__ + /* Clear the upper 32 bits. */ + movl %edx, %edx +# endif vpbroadcastb %xmm0, %ymm0 # endif /* Check if we may cross page boundary with one vector load. */ diff --git a/sysdeps/x86_64/x32/Makefile b/sysdeps/x86_64/x32/Makefile index f2ebc24fb0..7d528889c6 100644 --- a/sysdeps/x86_64/x32/Makefile +++ b/sysdeps/x86_64/x32/Makefile @@ -4,3 +4,11 @@ ifeq ($(subdir),math) # 64-bit llround. Add -fno-builtin-lround to silence the compiler. CFLAGS-s_llround.c += -fno-builtin-lround endif + +ifeq ($(subdir),string) +tests += tst-size_t-memchr +endif + +ifeq ($(subdir),wcsmbs) +tests += tst-size_t-wmemchr +endif diff --git a/sysdeps/x86_64/x32/test-size_t.h b/sysdeps/x86_64/x32/test-size_t.h new file mode 100644 index 0000000000..78a940863e --- /dev/null +++ b/sysdeps/x86_64/x32/test-size_t.h @@ -0,0 +1,35 @@ +/* Test string/memory functions with size_t in the lower 32 bits of + 64-bit register. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#define TEST_MAIN +#include + +/* On x32, parameter_t may be passed in a 64-bit register with the LEN + field in the lower 32 bits. When the LEN field of 64-bit register + is passed to string/memory function as the size_t parameter, only + the lower 32 bits can be used. */ +typedef struct +{ + union + { + size_t len; + void (*fn) (void); + }; + void *p; +} parameter_t; diff --git a/sysdeps/x86_64/x32/tst-size_t-memchr.c b/sysdeps/x86_64/x32/tst-size_t-memchr.c new file mode 100644 index 0000000000..29a3daf102 --- /dev/null +++ b/sysdeps/x86_64/x32/tst-size_t-memchr.c @@ -0,0 +1,72 @@ +/* Test memchr with size_t in the lower 32 bits of 64-bit register. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef WIDE +# define TEST_NAME "memchr" +#else +# define TEST_NAME "wmemchr" +#endif /* WIDE */ +#include "test-size_t.h" + +#ifndef WIDE +# define MEMCHR memchr +# define CHAR char +# define UCHAR unsigned char +#else +# include +# define MEMCHR wmemchr +# define CHAR wchar_t +# define UCHAR wchar_t +#endif /* WIDE */ + +IMPL (MEMCHR, 1) + +typedef CHAR * (*proto_t) (const CHAR*, int, size_t); + +static CHAR * +__attribute__ ((noinline, noclone)) +do_memchr (parameter_t a, parameter_t b) +{ + return CALL (&b, a.p, (uintptr_t) b.p, a.len); +} + +static int +test_main (void) +{ + test_init (); + + parameter_t src = { { page_size / sizeof (CHAR) }, buf2 }; + parameter_t c = { { 0 }, (void *) (uintptr_t) 0x12 }; + + int ret = 0; + FOR_EACH_IMPL (impl, 0) + { + c.fn = impl->fn; + CHAR *res = do_memchr (src, c); + if (res) + { + error (0, 0, "Wrong result in function %s: %p != NULL", + impl->name, res); + ret = 1; + } + } + + return ret ? EXIT_FAILURE : EXIT_SUCCESS; +} + +#include diff --git a/sysdeps/x86_64/x32/tst-size_t-wmemchr.c b/sysdeps/x86_64/x32/tst-size_t-wmemchr.c new file mode 100644 index 0000000000..877801d646 --- /dev/null +++ b/sysdeps/x86_64/x32/tst-size_t-wmemchr.c @@ -0,0 +1,20 @@ +/* Test wmemchr with size_t in the lower 32 bits of 64-bit register. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#define WIDE 1 +#include "tst-size_t-memchr.c"