The compression code in LZO never checked for output overruns.
Fix this by checking for end of buffer before each write.
Fixes: 64c70b1cf43d ("Add LZO1X algorithm to the kernel")
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index 47d6d43ea957..5d2f2f851694 100644
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -18,10 +18,10 @@
#include <linux/lzo.h>
#include "lzodefs.h"
-static noinline size_t
+static noinline int
lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
- unsigned char *out, size_t *out_len,
- size_t ti, void *wrkmem, signed char *state_offset,
+ unsigned char **out, unsigned char *op_end,
+ size_t *tp, void *wrkmem, signed char *state_offset,
const unsigned char bitstream_version)
{
const unsigned char *ip;
@@ -30,8 +30,9 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
const unsigned char * const ip_end = in + in_len - 20;
const unsigned char *ii;
lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
+ size_t ti = *tp;
- op = out;
+ op = *out;
ip = in;
ii = ip;
ip += ti < 4 ? 4 - ti : 0;
@@ -116,25 +117,41 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
if (t != 0) {
if (t <= 3) {
op[*state_offset] |= t;
+ if (!HAVE_OP(4))
+ return LZO_E_OUTPUT_OVERRUN;
COPY4(op, ii);
op += t;
} else if (t <= 16) {
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (t - 3);
+ if (!HAVE_OP(16))
+ return LZO_E_OUTPUT_OVERRUN;
COPY8(op, ii);
COPY8(op + 8, ii + 8);
op += t;
} else {
if (t <= 18) {
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (t - 3);
} else {
size_t tt = t - 18;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = 0;
while (unlikely(tt > 255)) {
tt -= 255;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = 0;
}
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = tt;
}
+ if (!HAVE_OP(t))
+ return LZO_E_OUTPUT_OVERRUN;
do {
COPY8(op, ii);
COPY8(op + 8, ii + 8);
@@ -151,6 +168,8 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
if (unlikely(run_length)) {
ip += run_length;
run_length -= MIN_ZERO_RUN_LENGTH;
+ if (!HAVE_OP(4))
+ return LZO_E_OUTPUT_OVERRUN;
put_unaligned_le32((run_length << 21) | 0xfffc18
| (run_length & 0x7), op);
op += 4;
@@ -243,10 +262,14 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
ip += m_len;
if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
m_off -= 1;
+ if (!HAVE_OP(2))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
*op++ = (m_off >> 3);
} else if (m_off <= M3_MAX_OFFSET) {
m_off -= 1;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
if (m_len <= M3_MAX_LEN)
*op++ = (M3_MARKER | (m_len - 2));
else {
@@ -254,14 +277,22 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
*op++ = M3_MARKER | 0;
while (unlikely(m_len > 255)) {
m_len -= 255;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = 0;
}
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (m_len);
}
+ if (!HAVE_OP(2))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (m_off << 2);
*op++ = (m_off >> 6);
} else {
m_off -= 0x4000;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
if (m_len <= M4_MAX_LEN)
*op++ = (M4_MARKER | ((m_off >> 11) & 8)
| (m_len - 2));
@@ -282,11 +313,17 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
m_len -= M4_MAX_LEN;
*op++ = (M4_MARKER | ((m_off >> 11) & 8));
while (unlikely(m_len > 255)) {
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
m_len -= 255;
*op++ = 0;
}
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (m_len);
}
+ if (!HAVE_OP(2))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (m_off << 2);
*op++ = (m_off >> 6);
}
@@ -295,14 +332,16 @@ lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
ii = ip;
goto next;
}
- *out_len = op - out;
- return in_end - (ii - ti);
+ *out = op;
+ *tp = in_end - (ii - ti);
+ return LZO_E_OK;
}
static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
unsigned char *out, size_t *out_len,
void *wrkmem, const unsigned char bitstream_version)
{
+ unsigned char * const op_end = out + *out_len;
const unsigned char *ip = in;
unsigned char *op = out;
unsigned char *data_start;
@@ -326,14 +365,17 @@ static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
while (l > 20) {
size_t ll = min_t(size_t, l, m4_max_offset + 1);
uintptr_t ll_end = (uintptr_t) ip + ll;
+ int err;
+
if ((ll_end + ((t + ll) >> 5)) <= ll_end)
break;
BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
- t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem,
- &state_offset, bitstream_version);
+ err = lzo1x_1_do_compress(ip, ll, &op, op_end, &t, wrkmem,
+ &state_offset, bitstream_version);
+ if (err != LZO_E_OK)
+ return err;
ip += ll;
- op += *out_len;
l -= ll;
}
t += l;
@@ -342,20 +384,32 @@ static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
const unsigned char *ii = in + in_len - t;
if (op == data_start && t <= 238) {
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (17 + t);
} else if (t <= 3) {
op[state_offset] |= t;
} else if (t <= 18) {
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = (t - 3);
} else {
size_t tt = t - 18;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = 0;
while (tt > 255) {
tt -= 255;
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = 0;
}
+ if (!HAVE_OP(1))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = tt;
}
+ if (!HAVE_OP(t))
+ return LZO_E_OUTPUT_OVERRUN;
if (t >= 16) do {
COPY8(op, ii);
COPY8(op + 8, ii + 8);
@@ -368,6 +422,8 @@ static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
} while (--t > 0);
}
+ if (!HAVE_OP(3))
+ return LZO_E_OUTPUT_OVERRUN;
*op++ = M4_MARKER | 1;
*op++ = 0;
*op++ = 0;
diff --git a/lib/lzo/lzo1x_decompress_safe.c b/lib/lzo/lzo1x_decompress_safe.c
index c94f4928e188..4d5a1b58a4a0 100644
--- a/lib/lzo/lzo1x_decompress_safe.c
+++ b/lib/lzo/lzo1x_decompress_safe.c
@@ -21,7 +21,6 @@
#include "lzodefs.h"
#define HAVE_IP(x) ((size_t)(ip_end - ip) >= (size_t)(x))
-#define HAVE_OP(x) ((size_t)(op_end - op) >= (size_t)(x))
#define NEED_IP(x) if (!HAVE_IP(x)) goto input_overrun
#define NEED_OP(x) if (!HAVE_OP(x)) goto output_overrun
#define TEST_LB(m_pos) if ((m_pos) < out) goto lookbehind_overrun
diff --git a/lib/lzo/lzodefs.h b/lib/lzo/lzodefs.h
index b60851fcf6ce..8b1a46993acf 100644
--- a/lib/lzo/lzodefs.h
+++ b/lib/lzo/lzodefs.h
@@ -19,6 +19,7 @@
*/
#define LZO_VERSION 1
+#define HAVE_OP(x) ((size_t)(op_end - op) >= (size_t)(x))
#define COPY4(dst, src) \
put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
#if defined(CONFIG_X86_64) || defined(CONFIG_ARM64)
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
