u-boot/lib/gunzip.c
Kees Cook b75650d84d gzip: correctly bounds-check output buffer
The output buffer size must not be reset by the gzip decoder or there
is a risk of overflowing memory during decompression.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
2013-09-03 13:30:14 -06:00

104 lines
2.1 KiB
C

/*
* (C) Copyright 2000-2006
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <watchdog.h>
#include <command.h>
#include <image.h>
#include <malloc.h>
#include <u-boot/zlib.h>
#define ZALLOC_ALIGNMENT 16
#define HEAD_CRC 2
#define EXTRA_FIELD 4
#define ORIG_NAME 8
#define COMMENT 0x10
#define RESERVED 0xe0
#define DEFLATED 8
void *gzalloc(void *x, unsigned items, unsigned size)
{
void *p;
size *= items;
size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
p = malloc (size);
return (p);
}
void gzfree(void *x, void *addr, unsigned nb)
{
free (addr);
}
int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
{
int i, flags;
/* skip header */
i = 10;
flags = src[3];
if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
puts ("Error: Bad gzipped data\n");
return (-1);
}
if ((flags & EXTRA_FIELD) != 0)
i = 12 + src[10] + (src[11] << 8);
if ((flags & ORIG_NAME) != 0)
while (src[i++] != 0)
;
if ((flags & COMMENT) != 0)
while (src[i++] != 0)
;
if ((flags & HEAD_CRC) != 0)
i += 2;
if (i >= *lenp) {
puts ("Error: gunzip out of data in header\n");
return (-1);
}
return zunzip(dst, dstlen, src, lenp, 1, i);
}
/*
* Uncompress blocks compressed with zlib without headers
*/
int zunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp,
int stoponerr, int offset)
{
z_stream s;
int r;
s.zalloc = gzalloc;
s.zfree = gzfree;
r = inflateInit2(&s, -MAX_WBITS);
if (r != Z_OK) {
printf ("Error: inflateInit2() returned %d\n", r);
return -1;
}
s.next_in = src + offset;
s.avail_in = *lenp - offset;
s.next_out = dst;
s.avail_out = dstlen;
do {
r = inflate(&s, Z_FINISH);
if (stoponerr == 1 && r != Z_STREAM_END &&
(s.avail_out == 0 || r != Z_BUF_ERROR)) {
printf("Error: inflate() returned %d\n", r);
inflateEnd(&s);
return -1;
}
s.avail_in = *lenp - offset - (int)(s.next_out - (unsigned char*)dst);
} while (r == Z_BUF_ERROR);
*lenp = s.next_out - (unsigned char *) dst;
inflateEnd(&s);
return 0;
}