From e6e209eb05545a36283335b07a1db9471cbccd1a Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 2 Mar 2022 13:56:00 -0800 Subject: [PATCH] x86-64 memcpy: Properly handle the length parameter [BZ #24097] 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 memcpy 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/multiarch/memcpy-ssse3-back.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memcpy-ssse3.S: Likewise. * sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S: Likewise. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcpy. tst-size_t-wmemchr. * sysdeps/x86_64/x32/tst-size_t-memcpy.c: New file. (cherry picked from commit 231c56760c1e2ded21ad96bbb860b1f08c556c7a) --- sysdeps/x86_64/multiarch/memcpy-ssse3-back.S | 17 ++++-- sysdeps/x86_64/multiarch/memcpy-ssse3.S | 17 ++++-- .../multiarch/memmove-avx512-no-vzeroupper.S | 16 +++-- .../multiarch/memmove-vec-unaligned-erms.S | 54 +++++++++-------- sysdeps/x86_64/x32/Makefile | 2 +- sysdeps/x86_64/x32/tst-size_t-memcpy.c | 58 +++++++++++++++++++ 6 files changed, 122 insertions(+), 42 deletions(-) create mode 100644 sysdeps/x86_64/x32/tst-size_t-memcpy.c diff --git a/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S b/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S index 3cd11233..568eebd3 100644 --- a/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S +++ b/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S @@ -45,28 +45,33 @@ .section .text.ssse3,"ax",@progbits #if !defined USE_AS_MEMPCPY && !defined USE_AS_MEMMOVE ENTRY (MEMPCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMPCPY_CHK) ENTRY (MEMPCPY) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start) END (MEMPCPY) #endif #if !defined USE_AS_BCOPY ENTRY (MEMCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMCPY_CHK) #endif ENTRY (MEMCPY) - mov %rdi, %rax + mov %RDI_LP, %RAX_LP #ifdef USE_AS_MEMPCPY - add %rdx, %rax + add %RDX_LP, %RAX_LP +#endif + +#ifdef __ILP32__ + /* Clear the upper 32 bits. */ + mov %edx, %edx #endif #ifdef USE_AS_MEMMOVE diff --git a/sysdeps/x86_64/multiarch/memcpy-ssse3.S b/sysdeps/x86_64/multiarch/memcpy-ssse3.S index 0240bfa3..0bd5ee99 100644 --- a/sysdeps/x86_64/multiarch/memcpy-ssse3.S +++ b/sysdeps/x86_64/multiarch/memcpy-ssse3.S @@ -45,28 +45,33 @@ .section .text.ssse3,"ax",@progbits #if !defined USE_AS_MEMPCPY && !defined USE_AS_MEMMOVE ENTRY (MEMPCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMPCPY_CHK) ENTRY (MEMPCPY) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start) END (MEMPCPY) #endif #if !defined USE_AS_BCOPY ENTRY (MEMCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMCPY_CHK) #endif ENTRY (MEMCPY) - mov %rdi, %rax + mov %RDI_LP, %RAX_LP #ifdef USE_AS_MEMPCPY - add %rdx, %rax + add %RDX_LP, %RAX_LP +#endif + +#ifdef __ILP32__ + /* Clear the upper 32 bits. */ + mov %edx, %edx #endif #ifdef USE_AS_MEMMOVE diff --git a/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S b/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S index effc3ac2..6ca2bbc9 100644 --- a/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S +++ b/sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S @@ -24,27 +24,31 @@ .section .text.avx512,"ax",@progbits ENTRY (__mempcpy_chk_avx512_no_vzeroupper) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (__mempcpy_chk_avx512_no_vzeroupper) ENTRY (__mempcpy_avx512_no_vzeroupper) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start) END (__mempcpy_avx512_no_vzeroupper) ENTRY (__memmove_chk_avx512_no_vzeroupper) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (__memmove_chk_avx512_no_vzeroupper) ENTRY (__memmove_avx512_no_vzeroupper) - mov %rdi, %rax + mov %RDI_LP, %RAX_LP # ifdef USE_AS_MEMPCPY - add %rdx, %rax + add %RDX_LP, %RAX_LP # endif L(start): +# ifdef __ILP32__ + /* Clear the upper 32 bits. */ + mov %edx, %edx +# endif lea (%rsi, %rdx), %rcx lea (%rdi, %rdx), %r9 cmp $512, %rdx diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S index c952576c..274aa1c7 100644 --- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S @@ -95,20 +95,20 @@ .section SECTION(.text),"ax",@progbits #if defined SHARED && IS_IN (libc) ENTRY (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned)) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned)) #endif ENTRY (MEMPCPY_SYMBOL (__mempcpy, unaligned)) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start) END (MEMPCPY_SYMBOL (__mempcpy, unaligned)) #if defined SHARED && IS_IN (libc) ENTRY (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned)) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned)) #endif @@ -116,9 +116,13 @@ END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned)) ENTRY (MEMMOVE_SYMBOL (__memmove, unaligned)) movq %rdi, %rax L(start): - cmpq $VEC_SIZE, %rdx +# ifdef __ILP32__ + /* Clear the upper 32 bits. */ + movl %edx, %edx +# endif + cmp $VEC_SIZE, %RDX_LP jb L(less_vec) - cmpq $(VEC_SIZE * 2), %rdx + cmp $(VEC_SIZE * 2), %RDX_LP ja L(more_2x_vec) #if !defined USE_MULTIARCH || !IS_IN (libc) L(last_2x_vec): @@ -138,38 +142,38 @@ END (MEMMOVE_SYMBOL (__memmove, unaligned)) # if VEC_SIZE == 16 ENTRY (__mempcpy_chk_erms) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (__mempcpy_chk_erms) /* Only used to measure performance of REP MOVSB. */ ENTRY (__mempcpy_erms) - movq %rdi, %rax + mov %RDI_LP, %RAX_LP /* Skip zero length. */ - testq %rdx, %rdx + test %RDX_LP, %RDX_LP jz 2f - addq %rdx, %rax + add %RDX_LP, %RAX_LP jmp L(start_movsb) END (__mempcpy_erms) ENTRY (__memmove_chk_erms) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (__memmove_chk_erms) ENTRY (__memmove_erms) movq %rdi, %rax /* Skip zero length. */ - testq %rdx, %rdx + test %RDX_LP, %RDX_LP jz 2f L(start_movsb): - movq %rdx, %rcx - cmpq %rsi, %rdi + mov %RDX_LP, %RCX_LP + cmp %RSI_LP, %RDI_LP jb 1f /* Source == destination is less common. */ je 2f - leaq (%rsi,%rcx), %rdx - cmpq %rdx, %rdi + lea (%rsi,%rcx), %RDX_LP + cmp %RDX_LP, %RDI_LP jb L(movsb_backward) 1: rep movsb @@ -189,20 +193,20 @@ strong_alias (__memmove_chk_erms, __memcpy_chk_erms) # ifdef SHARED ENTRY (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned_erms)) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMMOVE_CHK_SYMBOL (__mempcpy_chk, unaligned_erms)) # endif ENTRY (MEMMOVE_SYMBOL (__mempcpy, unaligned_erms)) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start_erms) END (MEMMOVE_SYMBOL (__mempcpy, unaligned_erms)) # ifdef SHARED ENTRY (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned_erms)) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned_erms)) # endif @@ -210,9 +214,13 @@ END (MEMMOVE_CHK_SYMBOL (__memmove_chk, unaligned_erms)) ENTRY (MEMMOVE_SYMBOL (__memmove, unaligned_erms)) movq %rdi, %rax L(start_erms): - cmpq $VEC_SIZE, %rdx +# ifdef __ILP32__ + /* Clear the upper 32 bits. */ + movl %edx, %edx +# endif + cmp $VEC_SIZE, %RDX_LP jb L(less_vec) - cmpq $(VEC_SIZE * 2), %rdx + cmp $(VEC_SIZE * 2), %RDX_LP ja L(movsb_more_2x_vec) L(last_2x_vec): /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */ @@ -236,7 +244,7 @@ L(movsb): /* Avoid slow backward REP MOVSB. */ jb L(more_8x_vec_backward) 1: - movq %rdx, %rcx + mov %RDX_LP, %RCX_LP rep movsb L(nop): ret diff --git a/sysdeps/x86_64/x32/Makefile b/sysdeps/x86_64/x32/Makefile index ddec7f04..2fe1e5ac 100644 --- a/sysdeps/x86_64/x32/Makefile +++ b/sysdeps/x86_64/x32/Makefile @@ -6,7 +6,7 @@ CFLAGS-s_llround.c += -fno-builtin-lround endif ifeq ($(subdir),string) -tests += tst-size_t-memchr tst-size_t-memcmp +tests += tst-size_t-memchr tst-size_t-memcmp tst-size_t-memcpy endif ifeq ($(subdir),wcsmbs) diff --git a/sysdeps/x86_64/x32/tst-size_t-memcpy.c b/sysdeps/x86_64/x32/tst-size_t-memcpy.c new file mode 100644 index 00000000..66b71e17 --- /dev/null +++ b/sysdeps/x86_64/x32/tst-size_t-memcpy.c @@ -0,0 +1,58 @@ +/* Test memcpy 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_NAME "memcpy" +#include "test-size_t.h" + +IMPL (memcpy, 1) + +typedef void *(*proto_t) (void *, const void *, size_t); + +static void * +__attribute__ ((noinline, noclone)) +do_memcpy (parameter_t a, parameter_t b) +{ + return CALL (&b, a.p, b.p, a.len); +} + +static int +test_main (void) +{ + test_init (); + + parameter_t dest = { { page_size }, buf1 }; + parameter_t src = { { 0 }, buf2 }; + + int ret = 0; + FOR_EACH_IMPL (impl, 0) + { + src.fn = impl->fn; + do_memcpy (dest, src); + int res = memcmp (dest.p, src.p, dest.len); + if (res) + { + error (0, 0, "Wrong result in function %s: %i != 0", + impl->name, res); + ret = 1; + } + } + + return ret ? EXIT_FAILURE : EXIT_SUCCESS; +} + +#include -- GitLab