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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-20 22:00:53 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-23 14:12:01 -0400
commit206a81c18401c0cde6e579164f752c4b147324ce (patch)
tree9a8eae6e89068e372ace1ac0a13af5c76b09faf9
parent7171511eaec5bf23fb06078f59784a3a0626b38f (diff)
lzo: properly check for overruns
The lzo decompressor can, if given some really crazy data, possibly overrun some variable types. Modify the checking logic to properly detect overruns before they happen. Reported-by: "Don A. Bailey" <donb@securitymouse.com> Tested-by: "Don A. Bailey" <donb@securitymouse.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--lib/lzo/lzo1x_decompress_safe.c62
1 files changed, 41 insertions, 21 deletions
diff --git a/lib/lzo/lzo1x_decompress_safe.c b/lib/lzo/lzo1x_decompress_safe.c
index 569985d522d5..8563081e8da3 100644
--- a/lib/lzo/lzo1x_decompress_safe.c
+++ b/lib/lzo/lzo1x_decompress_safe.c
@@ -19,11 +19,31 @@
#include <linux/lzo.h>
#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
+#define HAVE_IP(t, x) \
+ (((size_t)(ip_end - ip) >= (size_t)(t + x)) && \
+ (((t + x) >= t) && ((t + x) >= x)))
+
+#define HAVE_OP(t, x) \
+ (((size_t)(op_end - op) >= (size_t)(t + x)) && \
+ (((t + x) >= t) && ((t + x) >= x)))
+
+#define NEED_IP(t, x) \
+ do { \
+ if (!HAVE_IP(t, x)) \
+ goto input_overrun; \
+ } while (0)
+
+#define NEED_OP(t, x) \
+ do { \
+ if (!HAVE_OP(t, x)) \
+ goto output_overrun; \
+ } while (0)
+
+#define TEST_LB(m_pos) \
+ do { \
+ if ((m_pos) < out) \
+ goto lookbehind_overrun; \
+ } while (0)
int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
unsigned char *out, size_t *out_len)
@@ -58,14 +78,14 @@ int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
while (unlikely(*ip == 0)) {
t += 255;
ip++;
- NEED_IP(1);
+ NEED_IP(1, 0);
}
t += 15 + *ip++;
}
t += 3;
copy_literal_run:
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
- if (likely(HAVE_IP(t + 15) && HAVE_OP(t + 15))) {
+ if (likely(HAVE_IP(t, 15) && HAVE_OP(t, 15))) {
const unsigned char *ie = ip + t;
unsigned char *oe = op + t;
do {
@@ -81,8 +101,8 @@ copy_literal_run:
} else
#endif
{
- NEED_OP(t);
- NEED_IP(t + 3);
+ NEED_OP(t, 0);
+ NEED_IP(t, 3);
do {
*op++ = *ip++;
} while (--t > 0);
@@ -95,7 +115,7 @@ copy_literal_run:
m_pos -= t >> 2;
m_pos -= *ip++ << 2;
TEST_LB(m_pos);
- NEED_OP(2);
+ NEED_OP(2, 0);
op[0] = m_pos[0];
op[1] = m_pos[1];
op += 2;
@@ -119,10 +139,10 @@ copy_literal_run:
while (unlikely(*ip == 0)) {
t += 255;
ip++;
- NEED_IP(1);
+ NEED_IP(1, 0);
}
t += 31 + *ip++;
- NEED_IP(2);
+ NEED_IP(2, 0);
}
m_pos = op - 1;
next = get_unaligned_le16(ip);
@@ -137,10 +157,10 @@ copy_literal_run:
while (unlikely(*ip == 0)) {
t += 255;
ip++;
- NEED_IP(1);
+ NEED_IP(1, 0);
}
t += 7 + *ip++;
- NEED_IP(2);
+ NEED_IP(2, 0);
}
next = get_unaligned_le16(ip);
ip += 2;
@@ -154,7 +174,7 @@ copy_literal_run:
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
if (op - m_pos >= 8) {
unsigned char *oe = op + t;
- if (likely(HAVE_OP(t + 15))) {
+ if (likely(HAVE_OP(t, 15))) {
do {
COPY8(op, m_pos);
op += 8;
@@ -164,7 +184,7 @@ copy_literal_run:
m_pos += 8;
} while (op < oe);
op = oe;
- if (HAVE_IP(6)) {
+ if (HAVE_IP(6, 0)) {
state = next;
COPY4(op, ip);
op += next;
@@ -172,7 +192,7 @@ copy_literal_run:
continue;
}
} else {
- NEED_OP(t);
+ NEED_OP(t, 0);
do {
*op++ = *m_pos++;
} while (op < oe);
@@ -181,7 +201,7 @@ copy_literal_run:
#endif
{
unsigned char *oe = op + t;
- NEED_OP(t);
+ NEED_OP(t, 0);
op[0] = m_pos[0];
op[1] = m_pos[1];
op += 2;
@@ -194,15 +214,15 @@ match_next:
state = next;
t = next;
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
- if (likely(HAVE_IP(6) && HAVE_OP(4))) {
+ if (likely(HAVE_IP(6, 0) && HAVE_OP(4, 0))) {
COPY4(op, ip);
op += t;
ip += t;
} else
#endif
{
- NEED_IP(t + 3);
- NEED_OP(t);
+ NEED_IP(t, 3);
+ NEED_OP(t, 0);
while (t > 0) {
*op++ = *ip++;
t--;