u-boot/lib/gunzip.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2000-2006
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
#include <common.h>
#include <blk.h>
#include <command.h>
#include <console.h>
#include <div64.h>
#include <gzip.h>
#include <image.h>
#include <malloc.h>
#include <memalign.h>
#include <u-boot/crc.h>
#include <watchdog.h>
#include <u-boot/zlib.h>
#define HEADER0 '\x1f'
#define HEADER1 '\x8b'
#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 gzip_parse_header(const unsigned char *src, unsigned long len)
{
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 >= len) {
puts ("Error: gunzip out of data in header\n");
return (-1);
}
return i;
}
int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
{
int offset = gzip_parse_header(src, *lenp);
if (offset < 0)
return offset;
return zunzip(dst, dstlen, src, lenp, 1, offset);
}
#ifdef CONFIG_CMD_UNZIP
__weak
void gzwrite_progress_init(ulong expectedsize)
{
putc('\n');
}
__weak
void gzwrite_progress(int iteration,
ulong bytes_written,
ulong total_bytes)
{
if (0 == (iteration & 3))
printf("%lu/%lu\r", bytes_written, total_bytes);
}
__weak
void gzwrite_progress_finish(int returnval,
ulong bytes_written,
ulong total_bytes,
u32 expected_crc,
u32 calculated_crc)
{
if (0 == returnval) {
printf("\n\t%lu bytes, crc 0x%08x\n",
total_bytes, calculated_crc);
} else {
printf("\n\tuncompressed %lu of %lu\n"
"\tcrcs == 0x%08x/0x%08x\n",
bytes_written, total_bytes,
expected_crc, calculated_crc);
}
}
int gzwrite(unsigned char *src, int len,
struct blk_desc *dev,
unsigned long szwritebuf,
ulong startoffs,
ulong szexpected)
{
int i, flags;
z_stream s;
int r = 0;
unsigned char *writebuf;
unsigned crc = 0;
ulong totalfilled = 0;
lbaint_t blksperbuf, outblock;
u32 expected_crc;
u32 payload_size;
int iteration = 0;
if (!szwritebuf ||
(szwritebuf % dev->blksz) ||
(szwritebuf < dev->blksz)) {
printf("%s: size %lu not a multiple of %lu\n",
__func__, szwritebuf, dev->blksz);
return -1;
}
if (startoffs & (dev->blksz-1)) {
printf("%s: start offset %lu not a multiple of %lu\n",
__func__, startoffs, dev->blksz);
return -1;
}
blksperbuf = szwritebuf / dev->blksz;
outblock = lldiv(startoffs, dev->blksz);
/* 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 >= len-8) {
puts("Error: gunzip out of data in header");
return -1;
}
payload_size = len - i - 8;
memcpy(&expected_crc, src + len - 8, sizeof(expected_crc));
expected_crc = le32_to_cpu(expected_crc);
u32 szuncompressed;
memcpy(&szuncompressed, src + len - 4, sizeof(szuncompressed));
if (szexpected == 0) {
szexpected = le32_to_cpu(szuncompressed);
} else if (szuncompressed != (u32)szexpected) {
printf("size of %lx doesn't match trailer low bits %x\n",
szexpected, szuncompressed);
return -1;
}
if (lldiv(szexpected, dev->blksz) > (dev->lba - outblock)) {
printf("%s: uncompressed size %lu exceeds device size\n",
__func__, szexpected);
return -1;
}
gzwrite_progress_init(szexpected);
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 + i;
s.avail_in = payload_size+8;
writebuf = (unsigned char *)malloc_cache_aligned(szwritebuf);
/* decompress until deflate stream ends or end of file */
do {
if (s.avail_in == 0) {
printf("%s: weird termination with result %d\n",
__func__, r);
break;
}
/* run inflate() on input until output buffer not full */
do {
unsigned long blocks_written;
int numfilled;
lbaint_t writeblocks;
s.avail_out = szwritebuf;
s.next_out = writebuf;
r = inflate(&s, Z_SYNC_FLUSH);
if ((r != Z_OK) &&
(r != Z_STREAM_END)) {
printf("Error: inflate() returned %d\n", r);
goto out;
}
numfilled = szwritebuf - s.avail_out;
crc = crc32(crc, writebuf, numfilled);
totalfilled += numfilled;
if (numfilled < szwritebuf) {
writeblocks = (numfilled+dev->blksz-1)
/ dev->blksz;
memset(writebuf+numfilled, 0,
dev->blksz-(numfilled%dev->blksz));
} else {
writeblocks = blksperbuf;
}
gzwrite_progress(iteration++,
totalfilled,
szexpected);
blocks_written = blk_dwrite(dev, outblock,
writeblocks, writebuf);
outblock += blocks_written;
if (ctrlc()) {
puts("abort\n");
goto out;
}
schedule();
} while (s.avail_out == 0);
/* done when inflate() says it's done */
} while (r != Z_STREAM_END);
if ((szexpected != totalfilled) ||
(crc != expected_crc))
r = -1;
else
r = 0;
out:
gzwrite_progress_finish(r, totalfilled, szexpected,
expected_crc, crc);
free(writebuf);
inflateEnd(&s);
return r;
}
#endif
/*
* 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 err = 0;
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 &&
gunzip: remove avail_in recalculation Current, the following passes: ./u-boot -d arch/sandbox/dts/test.dtb -c 'ut_image_decomp' but the following fails: ./u-boot -d arch/sandbox/dts/test.dtb -c 'ut dm; ut_image_decomp' This is because the gunzip code reads input data beyond the end of its input buffer. In the first case above, this data just happens to be 0, which just happens to trigger gzip to signal the error the decompression unit test expects. In the second case above, the "ut dm" test has written data to the accidentally-read memory, which causes the gzip code to take a different path and so return a different value, which triggers the test failure. The cause of gunzip reading past its input buffer is the re-calculation of s.avail_in in zunzip(), since it can underflow. Not only is the formula non-sensical (it uses the delta between two output buffer pointers to calculate available input buffer size), it also appears to be unnecessary, since the gunzip code already maintains this value itself. This patch removes this re-calculation to avoid the underflow and redundant work. The loop exit condition is also adjusted so that if inflate() has consumed the entire input buffer, without indicating returning Z_STREAM_END (i.e. decompression complete without error), an error is raised. There is still opportunity to simplify the code here by splitting up the loop exit condition into separate tests. However, this patch makes the minimum modifications required to solve the problem at hand, in order to keep the Acked-by: Kees Cook <keescook@chromium.org> diff simple. I am not entirely convinced that the loop in zunzip() is necessary at all. It could only be useful if inflate() can return Z_BUF_ERROR (which typically means that it needs more data in the input buffer, or more space in the output buffer), even though Z_FINISH is set /and/ the full input is available in the input buffer /and/ there is enough space to store the decompressed output in the output buffer. The comment in zlib.h after the prototype of inflate() implies this is never the case. However, I assume there must have been some reason for introducing this loop in the first place, as part of commit "Fix gunzip to work for any gziped uImage size". This patch is similar to the earlier b75650d84d4b "gzip: correctly bounds-check output buffer", which corrected a similar issue for s.avail_out. Cc: Catalin Radu <Catalin@VirtualMetrix.com> Cc: Kees Cook <keescook@chromium.org> Fixes: f039ada5c109 ("Fix gunzip to work for any gziped uImage size") Signed-off-by: Stephen Warren <swarren@nvidia.com>
2016-01-29 20:26:58 +00:00
(s.avail_in == 0 || s.avail_out == 0 || r != Z_BUF_ERROR)) {
printf("Error: inflate() returned %d\n", r);
err = -1;
break;
}
} while (r == Z_BUF_ERROR);
*lenp = s.next_out - (unsigned char *) dst;
inflateEnd(&s);
return err;
}