Commit af958a38 authored by Willy Tarreau's avatar Willy Tarreau Committed by Greg Kroah-Hartman
Browse files

Revert "lzo: properly check for overruns" 



This reverts commit 206a81c1 ("lzo: properly check for overruns").

As analysed by Willem Pinckaers, this fix is still incomplete on
certain rare corner cases, and it is easier to restart from the
original code.

Reported-by: default avatarWillem Pinckaers <willem@lekkertech.net>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d98a0526

lib/lzo/lzo1x_decompress_safe.c

+21 −41
Original line number Diff line number Diff line
@@ -19,31 +19,11 @@ 
#include <linux/lzo.h>

#include "lzodefs.h"



#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)

#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



int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,

			  unsigned char *out, size_t *out_len)
@@ -78,14 +58,14 @@ int lzo1x_decompress_safe(const unsigned char *in, size_t in_len, 
					while (unlikely(*ip == 0)) {

						t += 255;

						ip++;

						NEED_IP(1, 0);

						NEED_IP(1);

					}

					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 {
@@ -101,8 +81,8 @@ copy_literal_run: 
				} else

#endif

				{

					NEED_OP(t, 0);

					NEED_IP(t, 3);

					NEED_OP(t);

					NEED_IP(t + 3);

					do {

						*op++ = *ip++;

					} while (--t > 0);
@@ -115,7 +95,7 @@ copy_literal_run: 
				m_pos -= t >> 2;

				m_pos -= *ip++ << 2;

				TEST_LB(m_pos);

				NEED_OP(2, 0);

				NEED_OP(2);

				op[0] = m_pos[0];

				op[1] = m_pos[1];

				op += 2;
@@ -139,10 +119,10 @@ copy_literal_run: 
				while (unlikely(*ip == 0)) {

					t += 255;

					ip++;

					NEED_IP(1, 0);

					NEED_IP(1);

				}

				t += 31 + *ip++;

				NEED_IP(2, 0);

				NEED_IP(2);

			}

			m_pos = op - 1;

			next = get_unaligned_le16(ip);
@@ -157,10 +137,10 @@ copy_literal_run: 
				while (unlikely(*ip == 0)) {

					t += 255;

					ip++;

					NEED_IP(1, 0);

					NEED_IP(1);

				}

				t += 7 + *ip++;

				NEED_IP(2, 0);

				NEED_IP(2);

			}

			next = get_unaligned_le16(ip);

			ip += 2;
@@ -174,7 +154,7 @@ 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;
@@ -184,7 +164,7 @@ copy_literal_run: 
					m_pos += 8;

				} while (op < oe);

				op = oe;

				if (HAVE_IP(6, 0)) {

				if (HAVE_IP(6)) {

					state = next;

					COPY4(op, ip);

					op += next;
@@ -192,7 +172,7 @@ copy_literal_run: 
					continue;

				}

			} else {

				NEED_OP(t, 0);

				NEED_OP(t);

				do {

					*op++ = *m_pos++;

				} while (op < oe);
@@ -201,7 +181,7 @@ copy_literal_run: 
#endif

		{

			unsigned char *oe = op + t;

			NEED_OP(t, 0);

			NEED_OP(t);

			op[0] = m_pos[0];

			op[1] = m_pos[1];

			op += 2;
@@ -214,15 +194,15 @@ match_next: 
		state = next;

		t = next;

#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)

		if (likely(HAVE_IP(6, 0) && HAVE_OP(4, 0))) {

		if (likely(HAVE_IP(6) && HAVE_OP(4))) {

			COPY4(op, ip);

			op += t;

			ip += t;

		} else

#endif

		{

			NEED_IP(t, 3);

			NEED_OP(t, 0);

			NEED_IP(t + 3);

			NEED_OP(t);

			while (t > 0) {

				*op++ = *ip++;

				t--;

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