mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Phillip Lougher](/assets/img/avatar_default.png)
If the lzma/gzip decompressors are called with insufficient input data (len > 0 & fill = NULL), they will attempt to call the fill function to obtain more data, leading to a kernel oops. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
176 lines
3.6 KiB
C
176 lines
3.6 KiB
C
#ifdef STATIC
|
|
/* Pre-boot environment: included */
|
|
|
|
/* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
|
|
* errors about console_printk etc... on ARM */
|
|
#define _LINUX_KERNEL_H
|
|
|
|
#include "zlib_inflate/inftrees.c"
|
|
#include "zlib_inflate/inffast.c"
|
|
#include "zlib_inflate/inflate.c"
|
|
|
|
#else /* STATIC */
|
|
/* initramfs et al: linked */
|
|
|
|
#include <linux/zutil.h>
|
|
|
|
#include "zlib_inflate/inftrees.h"
|
|
#include "zlib_inflate/inffast.h"
|
|
#include "zlib_inflate/inflate.h"
|
|
|
|
#include "zlib_inflate/infutil.h"
|
|
#include <linux/slab.h>
|
|
|
|
#endif /* STATIC */
|
|
|
|
#include <linux/decompress/mm.h>
|
|
|
|
#define GZIP_IOBUF_SIZE (16*1024)
|
|
|
|
static int nofill(void *buffer, unsigned int len)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
/* Included from initramfs et al code */
|
|
STATIC int INIT gunzip(unsigned char *buf, int len,
|
|
int(*fill)(void*, unsigned int),
|
|
int(*flush)(void*, unsigned int),
|
|
unsigned char *out_buf,
|
|
int *pos,
|
|
void(*error_fn)(char *x)) {
|
|
u8 *zbuf;
|
|
struct z_stream_s *strm;
|
|
int rc;
|
|
size_t out_len;
|
|
|
|
set_error_fn(error_fn);
|
|
rc = -1;
|
|
if (flush) {
|
|
out_len = 0x8000; /* 32 K */
|
|
out_buf = malloc(out_len);
|
|
} else {
|
|
out_len = 0x7fffffff; /* no limit */
|
|
}
|
|
if (!out_buf) {
|
|
error("Out of memory while allocating output buffer");
|
|
goto gunzip_nomem1;
|
|
}
|
|
|
|
if (buf)
|
|
zbuf = buf;
|
|
else {
|
|
zbuf = malloc(GZIP_IOBUF_SIZE);
|
|
len = 0;
|
|
}
|
|
if (!zbuf) {
|
|
error("Out of memory while allocating input buffer");
|
|
goto gunzip_nomem2;
|
|
}
|
|
|
|
strm = malloc(sizeof(*strm));
|
|
if (strm == NULL) {
|
|
error("Out of memory while allocating z_stream");
|
|
goto gunzip_nomem3;
|
|
}
|
|
|
|
strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
|
|
sizeof(struct inflate_state));
|
|
if (strm->workspace == NULL) {
|
|
error("Out of memory while allocating workspace");
|
|
goto gunzip_nomem4;
|
|
}
|
|
|
|
if (!fill)
|
|
fill = nofill;
|
|
|
|
if (len == 0)
|
|
len = fill(zbuf, GZIP_IOBUF_SIZE);
|
|
|
|
/* verify the gzip header */
|
|
if (len < 10 ||
|
|
zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
|
|
if (pos)
|
|
*pos = 0;
|
|
error("Not a gzip file");
|
|
goto gunzip_5;
|
|
}
|
|
|
|
/* skip over gzip header (1f,8b,08... 10 bytes total +
|
|
* possible asciz filename)
|
|
*/
|
|
strm->next_in = zbuf + 10;
|
|
/* skip over asciz filename */
|
|
if (zbuf[3] & 0x8) {
|
|
while (strm->next_in[0])
|
|
strm->next_in++;
|
|
strm->next_in++;
|
|
}
|
|
strm->avail_in = len - (strm->next_in - zbuf);
|
|
|
|
strm->next_out = out_buf;
|
|
strm->avail_out = out_len;
|
|
|
|
rc = zlib_inflateInit2(strm, -MAX_WBITS);
|
|
|
|
if (!flush) {
|
|
WS(strm)->inflate_state.wsize = 0;
|
|
WS(strm)->inflate_state.window = NULL;
|
|
}
|
|
|
|
while (rc == Z_OK) {
|
|
if (strm->avail_in == 0) {
|
|
/* TODO: handle case where both pos and fill are set */
|
|
len = fill(zbuf, GZIP_IOBUF_SIZE);
|
|
if (len < 0) {
|
|
rc = -1;
|
|
error("read error");
|
|
break;
|
|
}
|
|
strm->next_in = zbuf;
|
|
strm->avail_in = len;
|
|
}
|
|
rc = zlib_inflate(strm, 0);
|
|
|
|
/* Write any data generated */
|
|
if (flush && strm->next_out > out_buf) {
|
|
int l = strm->next_out - out_buf;
|
|
if (l != flush(out_buf, l)) {
|
|
rc = -1;
|
|
error("write error");
|
|
break;
|
|
}
|
|
strm->next_out = out_buf;
|
|
strm->avail_out = out_len;
|
|
}
|
|
|
|
/* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
|
|
if (rc == Z_STREAM_END) {
|
|
rc = 0;
|
|
break;
|
|
} else if (rc != Z_OK) {
|
|
error("uncompression error");
|
|
rc = -1;
|
|
}
|
|
}
|
|
|
|
zlib_inflateEnd(strm);
|
|
if (pos)
|
|
/* add + 8 to skip over trailer */
|
|
*pos = strm->next_in - zbuf+8;
|
|
|
|
gunzip_5:
|
|
free(strm->workspace);
|
|
gunzip_nomem4:
|
|
free(strm);
|
|
gunzip_nomem3:
|
|
if (!buf)
|
|
free(zbuf);
|
|
gunzip_nomem2:
|
|
if (flush)
|
|
free(out_buf);
|
|
gunzip_nomem1:
|
|
return rc; /* returns Z_OK (0) if successful */
|
|
}
|
|
|
|
#define decompress gunzip
|