1 Star 0 Fork 126

ZhangBo/qemu_src

forked from src-openEuler/qemu 
加入 Gitee
与超过 1200万 开发者一起发现、参与优秀开源项目,私有仓库也完全免费 :)
免费加入
文件
该仓库未声明开源许可证文件(LICENSE),使用请关注具体项目描述及其代码上游依赖。
克隆/下载
Use-post-increment-only-in-inffast.c.patch 9.53 KB
一键复制 编辑 原始数据 按行查看 历史
From 97021cac0565f57d14a3e285399dd2208c66c358 Mon Sep 17 00:00:00 2001
From: Yan Wang <wangyan122@huawei.com>
Date: Sat, 12 Feb 2022 15:00:25 +0800
Subject: [PATCH] Use post-increment only in inffast.c.
Fix CVE-2016-9841
patch link: https://github.com/madler/zlib/commit/9aaec95
An old inffast.c optimization turns out to not be optimal anymore
with modern compilers, and furthermore was not compliant with the
C standard, for which decrementing a pointer before its allocated
memory is undefined. Per the recommendation of a security audit of
the zlib code by Trail of Bits and TrustInSoft, in support of the
Mozilla Foundation, this "optimization" was removed, in order to
avoid the possibility of undefined behavior.
Signed-off-by: Yan Wang <wangyan122@huawei.com>
---
roms/u-boot/lib/zlib/inffast.c | 87 +++++++++++++++++-------------------------
1 file changed, 34 insertions(+), 53 deletions(-)
diff --git a/roms/u-boot/lib/zlib/inffast.c b/roms/u-boot/lib/zlib/inffast.c
index e3c7f3b..cdc778e 100644
--- a/roms/u-boot/lib/zlib/inffast.c
+++ b/roms/u-boot/lib/zlib/inffast.c
@@ -12,25 +12,6 @@
#ifndef ASMINF
-/* Allow machine dependent optimization for post-increment or pre-increment.
- Based on testing to date,
- Pre-increment preferred for:
- - PowerPC G3 (Adler)
- - MIPS R5000 (Randers-Pehrson)
- Post-increment preferred for:
- - none
- No measurable difference:
- - Pentium III (Anderson)
- - M68060 (Nikl)
- */
-#ifdef POSTINC
-# define OFF 0
-# define PUP(a) *(a)++
-#else
-# define OFF 1
-# define PUP(a) *++(a)
-#endif
-
/*
Decode literal, length, and distance codes and write out the resulting
literal and match bytes until either not enough input or output is
@@ -97,7 +78,7 @@ void inflate_fast(z_streamp strm, unsigned start)
/* copy state to local variables */
state = (struct inflate_state FAR *)strm->state;
- in = strm->next_in - OFF;
+ in = strm->next_in;
last = in + (strm->avail_in - 5);
if (in > last && strm->avail_in > 5) {
/*
@@ -107,7 +88,7 @@ void inflate_fast(z_streamp strm, unsigned start)
strm->avail_in = 0xffffffff - (uintptr_t)in;
last = in + (strm->avail_in - 5);
}
- out = strm->next_out - OFF;
+ out = strm->next_out;
beg = out - (start - strm->avail_out);
end = out + (strm->avail_out - 257);
#ifdef INFLATE_STRICT
@@ -128,9 +109,9 @@ void inflate_fast(z_streamp strm, unsigned start)
input data or output space */
do {
if (bits < 15) {
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
}
this = lcode[hold & lmask];
@@ -143,14 +124,14 @@ void inflate_fast(z_streamp strm, unsigned start)
Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", this.val));
- PUP(out) = (unsigned char)(this.val);
+ *out++ = (unsigned char)(this.val);
}
else if (op & 16) { /* length base */
len = (unsigned)(this.val);
op &= 15; /* number of extra bits */
if (op) {
if (bits < op) {
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
}
len += (unsigned)hold & ((1U << op) - 1);
@@ -159,9 +140,9 @@ void inflate_fast(z_streamp strm, unsigned start)
}
Tracevv((stderr, "inflate: length %u\n", len));
if (bits < 15) {
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
}
this = dcode[hold & dmask];
@@ -174,10 +155,10 @@ void inflate_fast(z_streamp strm, unsigned start)
dist = (unsigned)(this.val);
op &= 15; /* number of extra bits */
if (bits < op) {
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
if (bits < op) {
- hold += (unsigned long)(PUP(in)) << bits;
+ hold += (unsigned long)(*in++) << bits;
bits += 8;
}
}
@@ -200,13 +181,13 @@ void inflate_fast(z_streamp strm, unsigned start)
state->mode = BAD;
break;
}
- from = window - OFF;
+ from = window;
if (write == 0) { /* very common case */
from += wsize - op;
if (op < len) { /* some from window */
len -= op;
do {
- PUP(out) = PUP(from);
+ *out++ = *from++;
} while (--op);
from = out - dist; /* rest from output */
}
@@ -217,14 +198,14 @@ void inflate_fast(z_streamp strm, unsigned start)
if (op < len) { /* some from end of window */
len -= op;
do {
- PUP(out) = PUP(from);
+ *out++ = *from++;
} while (--op);
- from = window - OFF;
+ from = window;
if (write < len) { /* some from start of window */
op = write;
len -= op;
do {
- PUP(out) = PUP(from);
+ *out++ = *from++;
} while (--op);
from = out - dist; /* rest from output */
}
@@ -235,21 +216,21 @@ void inflate_fast(z_streamp strm, unsigned start)
if (op < len) { /* some from window */
len -= op;
do {
- PUP(out) = PUP(from);
+ *out++ = *from++;
} while (--op);
from = out - dist; /* rest from output */
}
}
while (len > 2) {
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
- PUP(out) = PUP(from);
+ *out++ = *from++;
+ *out++ = *from++;
+ *out++ = *from++;
len -= 3;
}
if (len) {
- PUP(out) = PUP(from);
+ *out++ = *from++;
if (len > 1)
- PUP(out) = PUP(from);
+ *out++ = *from++;
}
}
else {
@@ -259,25 +240,25 @@ void inflate_fast(z_streamp strm, unsigned start)
from = out - dist; /* copy direct from output */
/* minimum length is three */
/* Align out addr */
- if (!((long)(out - 1 + OFF) & 1)) {
- PUP(out) = PUP(from);
+ if (!((long)(out - 1) & 1)) {
+ *out++ = *from++;
len--;
}
- sout = (unsigned short *)(out - OFF);
+ sout = (unsigned short *)(out);
if (dist > 2 ) {
unsigned short *sfrom;
- sfrom = (unsigned short *)(from - OFF);
+ sfrom = (unsigned short *)(from);
loops = len >> 1;
do
- PUP(sout) = get_unaligned(++sfrom);
+ *sout++ = get_unaligned(++sfrom);
while (--loops);
- out = (unsigned char *)sout + OFF;
- from = (unsigned char *)sfrom + OFF;
+ out = (unsigned char *)sout;
+ from = (unsigned char *)sfrom;
} else { /* dist == 1 or dist == 2 */
unsigned short pat16;
- pat16 = *(sout-2+2*OFF);
+ pat16 = *(sout-2);
if (dist == 1)
#if defined(__BIG_ENDIAN)
pat16 = (pat16 & 0xff) | ((pat16 & 0xff ) << 8);
@@ -288,12 +269,12 @@ void inflate_fast(z_streamp strm, unsigned start)
#endif
loops = len >> 1;
do
- PUP(sout) = pat16;
+ *sout++ = pat16;
while (--loops);
- out = (unsigned char *)sout + OFF;
+ out = (unsigned char *)sout;
}
if (len & 1)
- PUP(out) = PUP(from);
+ *out++ = *from++;
}
}
else if ((op & 64) == 0) { /* 2nd level distance code */
@@ -329,8 +310,8 @@ void inflate_fast(z_streamp strm, unsigned start)
hold &= (1U << bits) - 1;
/* update state and return */
- strm->next_in = in + OFF;
- strm->next_out = out + OFF;
+ strm->next_in = in;
+ strm->next_out = out;
strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
strm->avail_out = (unsigned)(out < end ?
257 + (end - out) : 257 - (out - end));
--
1.9.1
Loading...
马建仓 AI 助手
尝试更多
代码解读
代码找茬
代码优化
1
https://gitee.com/ooorz/qemu_src.git
git@gitee.com:ooorz/qemu_src.git
ooorz
qemu_src
qemu_src
master

搜索帮助