From 26c7fdadcb7b829bc033ec8d0148385dd407f67b Mon Sep 17 00:00:00 2001 From: Huang Jianan Date: Sat, 26 Feb 2022 15:05:48 +0800 Subject: [PATCH] lib/lz4: update LZ4 decompressor module Update the LZ4 compression module based on LZ4 v1.8.3 in order to use the newest LZ4_decompress_safe_partial() which can now decode exactly the nb of bytes requested. Signed-off-by: Huang Jianan --- include/u-boot/lz4.h | 49 ++++ lib/lz4.c | 679 +++++++++++++++++++++++++++++++------------ lib/lz4_wrapper.c | 23 +- 3 files changed, 536 insertions(+), 215 deletions(-) diff --git a/include/u-boot/lz4.h b/include/u-boot/lz4.h index e18b39a5dc..655adbfcd1 100644 --- a/include/u-boot/lz4.h +++ b/include/u-boot/lz4.h @@ -21,4 +21,53 @@ */ int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn); +/** + * LZ4_decompress_safe() - Decompression protected against buffer overflow + * @source: source address of the compressed data + * @dest: output buffer address of the uncompressed data + * which must be already allocated + * @compressedSize: is the precise full size of the compressed block + * @maxDecompressedSize: is the size of 'dest' buffer + * + * Decompresses data from 'source' into 'dest'. + * If the source stream is detected malformed, the function will + * stop decoding and return a negative result. + * This function is protected against buffer overflow exploits, + * including malicious data packets. It never writes outside output buffer, + * nor reads outside input buffer. + * + * Return: number of bytes decompressed into destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + */ +int LZ4_decompress_safe(const char *source, char *dest, + int compressedSize, int maxDecompressedSize); + +/** + * LZ4_decompress_safe_partial() - Decompress a block of size 'compressedSize' + * at position 'source' into buffer 'dest' + * @source: source address of the compressed data + * @dest: output buffer address of the decompressed data which must be + * already allocated + * @compressedSize: is the precise full size of the compressed block. + * @targetOutputSize: the decompression operation will try + * to stop as soon as 'targetOutputSize' has been reached + * @maxDecompressedSize: is the size of destination buffer + * + * This function decompresses a compressed block of size 'compressedSize' + * at position 'source' into destination buffer 'dest' + * of size 'maxDecompressedSize'. + * The function tries to stop decompressing operation as soon as + * 'targetOutputSize' has been reached, reducing decompression time. + * This function never writes outside of output buffer, + * and never reads outside of input buffer. + * It is therefore protected against malicious data packets. + * + * Return: the number of bytes decoded in the destination buffer + * (necessarily <= maxDecompressedSize) + * or a negative result in case of error + * + */ +int LZ4_decompress_safe_partial(const char *src, char *dst, + int compressedSize, int targetOutputSize, int dstCapacity); #endif diff --git a/lib/lz4.c b/lib/lz4.c index 046c34e390..5337842126 100644 --- a/lib/lz4.c +++ b/lib/lz4.c @@ -1,13 +1,63 @@ -// SPDX-License-Identifier: BSD-2-Clause +// SPDX-License-Identifier: GPL 2.0+ OR BSD-2-Clause /* - LZ4 - Fast LZ compression algorithm - Copyright (C) 2011-2015, Yann Collet. + * LZ4 - Fast LZ compression algorithm + * Copyright (C) 2011 - 2016, Yann Collet. + * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php) + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * You can contact the author at : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 + */ +#include +#include +#include +#include +#include +#include +#include + +#define FORCE_INLINE inline __attribute__((always_inline)) + +static FORCE_INLINE u16 LZ4_readLE16(const void *src) +{ + return get_unaligned_le16(src); +} - You can contact the author at : - - LZ4 source repository : https://github.com/Cyan4973/lz4 - - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c -*/ +static FORCE_INLINE void LZ4_copy8(void *dst, const void *src) +{ + put_unaligned(get_unaligned((const u64 *)src), (u64 *)dst); +} + +typedef uint8_t BYTE; +typedef uint16_t U16; +typedef uint32_t U32; +typedef int32_t S32; +typedef uint64_t U64; +typedef uintptr_t uptrval; +static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value) +{ + put_unaligned(value, (U32 *)memPtr); +} /************************************** * Reading and writing into memory @@ -28,14 +78,17 @@ static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd) **************************************/ #define MINMATCH 4 -#define COPYLENGTH 8 +#define WILDCOPYLENGTH 8 #define LASTLITERALS 5 -#define MFLIMIT (COPYLENGTH+MINMATCH) -static const int LZ4_minLength = (MFLIMIT+1); +#define MFLIMIT (WILDCOPYLENGTH + MINMATCH) -#define KB *(1 <<10) -#define MB *(1 <<20) -#define GB *(1U<<30) +/* + * ensure it's possible to write 2 x wildcopyLength + * without overflowing output buffer + */ +#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH) + +#define KB (1 <<10) #define MAXD_LOG 16 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1) @@ -45,198 +98,438 @@ static const int LZ4_minLength = (MFLIMIT+1); #define RUN_BITS (8-ML_BITS) #define RUN_MASK ((1U< oend-MFLIMIT)) oexit = oend-MFLIMIT; /* targetOutputSize too high => decode everything */ - if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */ - if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1); - - - /* Main Loop */ - while (1) - { - unsigned token; - size_t length; - const BYTE* match; - - /* get literal length */ - token = *ip++; - if ((length=(token>>ML_BITS)) == RUN_MASK) - { - unsigned s; - do - { - s = *ip++; - length += s; - } - while (likely((endOnInput)?ip(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) ) - || ((!endOnInput) && (cpy>oend-COPYLENGTH))) - { - if (partialDecoding) - { - if (cpy > oend) goto _output_error; /* Error : write attempt beyond end of output buffer */ - if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */ - } - else - { - if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */ - if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) goto _output_error; /* Error : input must be consumed */ - } - memcpy(op, ip, length); - ip += length; - op += length; - break; /* Necessarily EOF, due to parsing restrictions */ - } - LZ4_wildCopy(op, ip, cpy); - ip += length; op = cpy; - - /* get offset */ - match = cpy - LZ4_readLE16(ip); ip+=2; - if ((checkOffset) && (unlikely(match < lowLimit))) goto _output_error; /* Error : offset outside destination buffer */ - - /* get matchlength */ - length = token & ML_MASK; - if (length == ML_MASK) - { - unsigned s; - do - { - if ((endOnInput) && (ip > iend-LASTLITERALS)) goto _output_error; - s = *ip++; - length += s; - } while (s==255); - if ((safeDecode) && unlikely((size_t)(op+length)<(size_t)op)) goto _output_error; /* overflow detection */ - } - length += MINMATCH; - - /* check external dictionary */ - if ((dict==usingExtDict) && (match < lowPrefix)) - { - if (unlikely(op+length > oend-LASTLITERALS)) goto _output_error; /* doesn't respect parsing restriction */ - - if (length <= (size_t)(lowPrefix-match)) - { - /* match can be copied as a single segment from external dictionary */ - match = dictEnd - (lowPrefix-match); - memmove(op, match, length); op += length; - } - else - { - /* match encompass external dictionary and current segment */ - size_t copySize = (size_t)(lowPrefix-match); - memcpy(op, dictEnd - copySize, copySize); - op += copySize; - copySize = length - copySize; - if (copySize > (size_t)(op-lowPrefix)) /* overlap within current segment */ - { - BYTE* const endOfMatch = op + copySize; - const BYTE* copyFrom = lowPrefix; - while (op < endOfMatch) *op++ = *copyFrom++; - } - else - { - memcpy(op, lowPrefix, copySize); - op += copySize; - } - } - continue; - } - - /* copy repeated sequence */ - cpy = op + length; - if (unlikely((op-match)<8)) - { - const size_t dec64 = dec64table[op-match]; - op[0] = match[0]; - op[1] = match[1]; - op[2] = match[2]; - op[3] = match[3]; - match += dec32table[op-match]; - LZ4_copy4(op+4, match); - op += 8; match -= dec64; - } else { LZ4_copy8(op, match); op+=8; match+=8; } - - if (unlikely(cpy>oend-12)) - { - if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals */ - if (op < oend-8) - { - LZ4_wildCopy(op, match, oend-8); - match += (oend-8) - op; - op = oend-8; - } - while (op>ML_BITS; + + /* ip < iend before the increment */ + assert(!endOnInput || ip <= iend); + + /* + * A two-stage shortcut for the most common case: + * 1) If the literal length is 0..14, and there is enough + * space, enter the shortcut and copy 16 bytes on behalf + * of the literals (in the fast mode, only 8 bytes can be + * safely copied this way). + * 2) Further if the match length is 4..18, copy 18 bytes + * in a similar manner; but we ensure that there's enough + * space in the output for those 18 bytes earlier, upon + * entering the shortcut (in other words, there is a + * combined check for both stages). + * + * The & in the likely() below is intentionally not && so that + * some compilers can produce better parallelized runtime code + */ + if ((endOnInput ? length != RUN_MASK : length <= 8) + /* + * strictly "less than" on input, to re-enter + * the loop with at least one byte + */ + && likely((endOnInput ? ip < shortiend : 1) & + (op <= shortoend))) { + /* Copy the literals */ + memcpy(op, ip, endOnInput ? 16 : 8); + op += length; ip += length; + + /* + * The second stage: + * prepare for match copying, decode full info. + * If it doesn't work out, the info won't be wasted. + */ + length = token & ML_MASK; /* match length */ + offset = LZ4_readLE16(ip); + ip += 2; + match = op - offset; + assert(match <= op); /* check overflow */ + + /* Do not deal with overlapping matches. */ + if ((length != ML_MASK) && + (offset >= 8) && + (dict == withPrefix64k || match >= lowPrefix)) { + /* Copy the match. */ + memcpy(op + 0, match + 0, 8); + memcpy(op + 8, match + 8, 8); + memcpy(op + 16, match + 16, 2); + op += length + MINMATCH; + /* Both stages worked, load the next token. */ + continue; + } + + /* + * The second stage didn't work out, but the info + * is ready. Propel it right to the point of match + * copying. + */ + goto _copy_match; + } + + /* decode literal length */ + if (length == RUN_MASK) { + unsigned int s; + + if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) { + /* overflow detection */ + goto _output_error; + } + do { + s = *ip++; + length += s; + } while (likely(endOnInput + ? ip < iend - RUN_MASK + : 1) & (s == 255)); + + if ((safeDecode) + && unlikely((uptrval)(op) + + length < (uptrval)(op))) { + /* overflow detection */ + goto _output_error; + } + if ((safeDecode) + && unlikely((uptrval)(ip) + + length < (uptrval)(ip))) { + /* overflow detection */ + goto _output_error; + } + } + + /* copy literals */ + cpy = op + length; + LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); + + if (((endOnInput) && ((cpy > oend - MFLIMIT) + || (ip + length > iend - (2 + 1 + LASTLITERALS)))) + || ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) { + if (partialDecoding) { + if (cpy > oend) { + /* + * Partial decoding : + * stop in the middle of literal segment + */ + cpy = oend; + length = oend - op; + } + if ((endOnInput) + && (ip + length > iend)) { + /* + * Error : + * read attempt beyond + * end of input buffer + */ + goto _output_error; + } + } else { + if ((!endOnInput) + && (cpy != oend)) { + /* + * Error : + * block decoding must + * stop exactly there + */ + goto _output_error; + } + if ((endOnInput) + && ((ip + length != iend) + || (cpy > oend))) { + /* + * Error : + * input must be consumed + */ + goto _output_error; + } + } + + /* + * supports overlapping memory regions; only matters + * for in-place decompression scenarios + */ + memmove(op, ip, length); + ip += length; + op += length; + + /* Necessarily EOF, due to parsing restrictions */ + if (!partialDecoding || (cpy == oend)) + break; + } else { + /* may overwrite up to WILDCOPYLENGTH beyond cpy */ + LZ4_wildCopy(op, ip, cpy); + ip += length; + op = cpy; + } + + /* get offset */ + offset = LZ4_readLE16(ip); + ip += 2; + match = op - offset; + + /* get matchlength */ + length = token & ML_MASK; + +_copy_match: + if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) { + /* Error : offset outside buffers */ + goto _output_error; + } + + /* costs ~1%; silence an msan warning when offset == 0 */ + /* + * note : when partialDecoding, there is no guarantee that + * at least 4 bytes remain available in output buffer + */ + if (!partialDecoding) { + assert(oend > op); + assert(oend - op >= 4); + + LZ4_write32(op, (U32)offset); + } + + if (length == ML_MASK) { + unsigned int s; + + do { + s = *ip++; + + if ((endOnInput) && (ip > iend - LASTLITERALS)) + goto _output_error; + + length += s; + } while (s == 255); + + if ((safeDecode) + && unlikely( + (uptrval)(op) + length < (uptrval)op)) { + /* overflow detection */ + goto _output_error; + } + } + + length += MINMATCH; + + /* match starting within external dictionary */ + if ((dict == usingExtDict) && (match < lowPrefix)) { + if (unlikely(op + length > oend - LASTLITERALS)) { + /* doesn't respect parsing restriction */ + if (!partialDecoding) + goto _output_error; + length = min(length, (size_t)(oend - op)); + } + + if (length <= (size_t)(lowPrefix - match)) { + /* + * match fits entirely within external + * dictionary : just copy + */ + memmove(op, dictEnd - (lowPrefix - match), + length); + op += length; + } else { + /* + * match stretches into both external + * dictionary and current block + */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + + memcpy(op, dictEnd - copySize, copySize); + op += copySize; + if (restSize > (size_t)(op - lowPrefix)) { + /* overlap copy */ + BYTE * const endOfMatch = op + restSize; + const BYTE *copyFrom = lowPrefix; + + while (op < endOfMatch) + *op++ = *copyFrom++; + } else { + memcpy(op, lowPrefix, restSize); + op += restSize; + } + } + continue; + } + + /* copy match within block */ + cpy = op + length; + + /* + * partialDecoding : + * may not respect endBlock parsing restrictions + */ + assert(op <= oend); + if (partialDecoding && + (cpy > oend - MATCH_SAFEGUARD_DISTANCE)) { + size_t const mlen = min(length, (size_t)(oend - op)); + const BYTE * const matchEnd = match + mlen; + BYTE * const copyEnd = op + mlen; + + if (matchEnd > op) { + /* overlap copy */ + while (op < copyEnd) + *op++ = *match++; + } else { + memcpy(op, match, mlen); + } + op = copyEnd; + if (op == oend) + break; + continue; + } + + if (unlikely(offset < 8)) { + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += inc32table[offset]; + memcpy(op + 4, match, 4); + match -= dec64table[offset]; + } else { + LZ4_copy8(op, match); + match += 8; + } + + op += 8; + + if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) { + BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1); + + if (cpy > oend - LASTLITERALS) { + /* + * Error : last LASTLITERALS bytes + * must be literals (uncompressed) + */ + goto _output_error; + } + + if (op < oCopyLimit) { + LZ4_wildCopy(op, match, oCopyLimit); + match += oCopyLimit - op; + op = oCopyLimit; + } + while (op < cpy) + *op++ = *match++; + } else { + LZ4_copy8(op, match); + if (length > 16) + LZ4_wildCopy(op + 8, match + 8, cpy); + } + op = cpy; /* wildcopy correction */ + } + + /* end of decoding */ + if (endOnInput) { + /* Nb of output bytes decoded */ + return (int) (((char *)op) - dst); + } else { + /* Nb of input bytes read */ + return (int) (((const char *)ip) - src); + } + + /* Overflow error detected */ _output_error: - return (int) (-(((const char*)ip)-source))-1; + return (int) (-(((const char *)ip) - src)) - 1; +} + +int LZ4_decompress_safe(const char *source, char *dest, + int compressedSize, int maxDecompressedSize) +{ + return LZ4_decompress_generic(source, dest, + compressedSize, maxDecompressedSize, + endOnInputSize, decode_full_block, + noDict, (BYTE *)dest, NULL, 0); +} + +int LZ4_decompress_safe_partial(const char *src, char *dst, + int compressedSize, int targetOutputSize, int dstCapacity) +{ + dstCapacity = min(targetOutputSize, dstCapacity); + return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity, + endOnInputSize, partial_decode, + noDict, (BYTE *)dst, NULL, 0); } diff --git a/lib/lz4_wrapper.c b/lib/lz4_wrapper.c index ebcb5c09a2..0d2a3655a8 100644 --- a/lib/lz4_wrapper.c +++ b/lib/lz4_wrapper.c @@ -11,27 +11,6 @@ #include #include -static u16 LZ4_readLE16(const void *src) -{ - return get_unaligned_le16(src); -} -static void LZ4_copy4(void *dst, const void *src) -{ - put_unaligned(get_unaligned((const u32 *)src), (u32 *)dst); -} -static void LZ4_copy8(void *dst, const void *src) -{ - put_unaligned(get_unaligned((const u64 *)src), (u64 *)dst); -} - -typedef uint8_t BYTE; -typedef uint16_t U16; -typedef uint32_t U32; -typedef int32_t S32; -typedef uint64_t U64; - -#define FORCE_INLINE static inline __attribute__((always_inline)) - /* lz4.c is unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */ #include "lz4.c" /* #include for inlining, do not link! */ @@ -112,7 +91,7 @@ int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn) /* constant folding essential, do not touch params! */ ret = LZ4_decompress_generic(in, out, block_size, end - out, endOnInputSize, - full, 0, noDict, out, NULL, 0); + decode_full_block, noDict, out, NULL, 0); if (ret < 0) { ret = -EPROTO; /* decompression error */ break; -- 2.39.5