[g]unzip: fix recent breakage.
Also, do emit error message we so painstakingly pass from gzip internals
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/libarchive/decompress_gunzip.c b/archival/libarchive/decompress_gunzip.c
index 30bf451..20e4d9a 100644
--- a/archival/libarchive/decompress_gunzip.c
+++ b/archival/libarchive/decompress_gunzip.c
@@ -309,8 +309,7 @@
huft_t *q; /* points to current table */
huft_t r; /* table entry for structure assignment */
huft_t *u[BMAX]; /* table stack */
- unsigned v[N_MAX]; /* values in order of bit length */
- unsigned v_end;
+ unsigned v[N_MAX + 1]; /* values in order of bit length. last v[] is never used */
int ws[BMAX + 1]; /* bits decoded stack */
int w; /* bits decoded */
unsigned x[BMAX + 1]; /* bit offsets, then code stack */
@@ -365,15 +364,17 @@
*xp++ = j;
}
- /* Make a table of values in order of bit lengths */
+ /* Make a table of values in order of bit lengths.
+ * To detect bad input, unused v[i]'s are set to invalid value UINT_MAX.
+ * In particular, last v[i] is never filled and must not be accessed.
+ */
+ memset(v, 0xff, sizeof(v));
p = b;
i = 0;
- v_end = 0;
do {
j = *p++;
if (j != 0) {
v[x[j]++] = i;
- v_end = x[j];
}
} while (++i < n);
@@ -435,7 +436,9 @@
/* set up table entry in r */
r.b = (unsigned char) (k - w);
- if (p >= v + v_end) { // Was "if (p >= v + n)" but v[] can be shorter!
+ if (/*p >= v + n || -- redundant, caught by the second check: */
+ *p == UINT_MAX /* do we access uninited v[i]? (see memset(v))*/
+ ) {
r.e = 99; /* out of values--invalid code */
} else if (*p < s) {
r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is EOB code */
@@ -520,8 +523,9 @@
e = t->e;
if (e > 16)
do {
- if (e == 99)
- abort_unzip(PASS_STATE_ONLY);;
+ if (e == 99) {
+ abort_unzip(PASS_STATE_ONLY);
+ }
bb >>= t->b;
k -= t->b;
e -= 16;
@@ -557,8 +561,9 @@
e = t->e;
if (e > 16)
do {
- if (e == 99)
+ if (e == 99) {
abort_unzip(PASS_STATE_ONLY);
+ }
bb >>= t->b;
k -= t->b;
e -= 16;
@@ -824,8 +829,9 @@
b_dynamic >>= 4;
k_dynamic -= 4;
- if (nl > 286 || nd > 30)
+ if (nl > 286 || nd > 30) {
abort_unzip(PASS_STATE_ONLY); /* bad lengths */
+ }
/* read in bit-length-code lengths */
for (j = 0; j < nb; j++) {
@@ -906,12 +912,14 @@
bl = lbits;
i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
- if (i != 0)
+ if (i != 0) {
abort_unzip(PASS_STATE_ONLY);
+ }
bd = dbits;
i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
- if (i != 0)
+ if (i != 0) {
abort_unzip(PASS_STATE_ONLY);
+ }
/* set up data for inflate_codes() */
inflate_codes_setup(PASS_STATE bl, bd);
@@ -999,6 +1007,7 @@
error_msg = "corrupted data";
if (setjmp(error_jmp)) {
/* Error from deep inside zip machinery */
+ bb_error_msg(error_msg);
n = -1;
goto ret;
}