Correct multiple vulnerabilities in gzip(1).

Security:	FreeBSD-SA-06:21.gzip
This commit is contained in:
Simon L. B. Nielsen 2006-09-19 14:06:20 +00:00
parent f37e633887
commit 789cb6fc6a
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=162445
4 changed files with 25 additions and 20 deletions

View file

@ -202,6 +202,8 @@ extern int test; /* check .z file integrity */
extern int to_stdout; /* output to stdout (-c) */
extern int save_orig_name; /* set if original name must be saved */
#define MIN(a,b) ((a) <= (b) ? (a) : (b))
#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
#define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))

View file

@ -316,7 +316,7 @@ int *m; /* maximum lookup bits, returns actual */
{
*t = (struct huft *)NULL;
*m = 0;
return 0;
return 2;
}

View file

@ -148,13 +148,17 @@ local void make_table(nchar, bitlen, tablebits, table)
unsigned i, k, len, ch, jutbits, avail, nextcode, mask;
for (i = 1; i <= 16; i++) count[i] = 0;
for (i = 0; i < (unsigned)nchar; i++) count[bitlen[i]]++;
for (i = 0; i < (unsigned)nchar; i++) {
if (bitlen[i] > 16)
error("Bad table (case a)\n");
else count[bitlen[i]]++;
}
start[1] = 0;
for (i = 1; i <= 16; i++)
start[i + 1] = start[i] + (count[i] << (16 - i));
if ((start[17] & 0xffff) != 0)
error("Bad table\n");
if ((start[17] & 0xffff) != 0 || tablebits > 16) /* 16 for weight below */
error("Bad table (case b)\n");
jutbits = 16 - tablebits;
for (i = 1; i <= (unsigned)tablebits; i++) {
@ -168,15 +172,15 @@ local void make_table(nchar, bitlen, tablebits, table)
i = start[tablebits + 1] >> jutbits;
if (i != 0) {
k = 1 << tablebits;
while (i != k) table[i++] = 0;
k = MIN(1 << tablebits, DIST_BUFSIZE);
while (i < k) table[i++] = 0;
}
avail = nchar;
mask = (unsigned) 1 << (15 - tablebits);
for (ch = 0; ch < (unsigned)nchar; ch++) {
if ((len = bitlen[ch]) == 0) continue;
nextcode = start[len] + weight[len];
nextcode = MIN(start[len] + weight[len], DIST_BUFSIZE);
if (len <= (unsigned)tablebits) {
for (i = start[len]; i < nextcode; i++) table[i] = ch;
} else {
@ -217,7 +221,7 @@ local void read_pt_len(nn, nbit, i_special)
for (i = 0; i < 256; i++) pt_table[i] = c;
} else {
i = 0;
while (i < n) {
while (i < MIN(n,NPT)) {
c = bitbuf >> (BITBUFSIZ - 3);
if (c == 7) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 3);
@ -227,7 +231,7 @@ local void read_pt_len(nn, nbit, i_special)
pt_len[i++] = c;
if (i == i_special) {
c = getbits(2);
while (--c >= 0) pt_len[i++] = 0;
while (--c >= 0 && i < NPT) pt_len[i++] = 0;
}
}
while (i < nn) pt_len[i++] = 0;
@ -247,7 +251,7 @@ local void read_c_len()
for (i = 0; i < 4096; i++) c_table[i] = c;
} else {
i = 0;
while (i < n) {
while (i < MIN(n,NC)) {
c = pt_table[bitbuf >> (BITBUFSIZ - 8)];
if (c >= NT) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 8);
@ -255,14 +259,14 @@ local void read_c_len()
if (bitbuf & mask) c = right[c];
else c = left [c];
mask >>= 1;
} while (c >= NT);
} while (c >= NT && (mask || c != left[c]));
}
fillbuf((int) pt_len[c]);
if (c <= 2) {
if (c == 0) c = 1;
else if (c == 1) c = getbits(4) + 3;
else c = getbits(CBIT) + 20;
while (--c >= 0) c_len[i++] = 0;
while (--c >= 0 && i < NC) c_len[i++] = 0;
} else c_len[i++] = c - 2;
}
while (i < NC) c_len[i++] = 0;
@ -291,7 +295,7 @@ local unsigned decode_c()
if (bitbuf & mask) j = right[j];
else j = left [j];
mask >>= 1;
} while (j >= NC);
} while (j >= NC && (mask || j != left[j]));
}
fillbuf((int) c_len[j]);
return j;
@ -308,7 +312,7 @@ local unsigned decode_p()
if (bitbuf & mask) j = right[j];
else j = left [j];
mask >>= 1;
} while (j >= NP);
} while (j >= NP && (mask || j != left[j]));
}
fillbuf((int) pt_len[j]);
if (j != 0) j = ((unsigned) 1 << (j - 1)) + getbits((int) (j - 1));
@ -355,7 +359,7 @@ local unsigned decode(count, buffer)
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count) return r;
if (++r >= count) return r;
}
for ( ; ; ) {
c = decode_c();
@ -365,14 +369,14 @@ local unsigned decode(count, buffer)
}
if (c <= UCHAR_MAX) {
buffer[r] = c;
if (++r == count) return r;
if (++r >= count) return r;
} else {
j = c - (UCHAR_MAX + 1 - THRESHOLD);
i = (r - decode_p() - 1) & (DICSIZ - 1);
while (--j >= 0) {
buffer[r] = buffer[i];
i = (i + 1) & (DICSIZ - 1);
if (++r == count) return r;
if (++r >= count) return r;
}
}
}

View file

@ -12,7 +12,6 @@ static char rcsid[] = "$FreeBSD$";
#include "gzip.h"
#include "crypt.h"
#define MIN(a,b) ((a) <= (b) ? (a) : (b))
/* The arguments must not have side effects. */
#define MAX_BITLEN 25
@ -132,7 +131,7 @@ local void read_tree()
/* Remember where the literals of this length start in literal[] : */
lit_base[len] = base;
/* And read the literals: */
for (n = leaves[len]; n > 0; n--) {
for (n = leaves[len]; n > 0 && base < LITERALS; n--) {
literal[base++] = (uch)get_byte();
}
}
@ -168,7 +167,7 @@ local void build_tree()
prefixp = &prefix_len[1<<peek_bits];
for (len = 1; len <= peek_bits; len++) {
int prefixes = leaves[len] << (peek_bits-len); /* may be 0 */
while (prefixes--) *--prefixp = (uch)len;
while (prefixes-- && prefixp > prefix_len) *--prefixp = (uch)len;
}
/* The length of all other codes is unknown: */
while (prefixp > prefix_len) *--prefixp = 0;