From 465d167ad2f6a67d0b2c91fb6c68c8f9a09dd395 Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Sat, 10 Aug 2013 09:35:56 -0700 Subject: [PATCH] LZMA: Add a version of ulzma which takes the input and output buffer sizes. This version is used to implement the version which doesn't. BUG=chromium:270897 TEST=Built into depthcharge and booted on pit. BRANCH=None Change-Id: I8935024aca0849bc939263d7fc3036c586e63c68 Signed-off-by: Gabe Black Reviewed-on: https://gerrit.chromium.org/gerrit/65510 Reviewed-by: Kees Cook Reviewed-by: Stefan Reinauer Tested-by: Gabe Black Commit-Queue: Gabe Black --- payloads/libpayload/include/lzma.h | 12 ++++++++++-- payloads/libpayload/liblzma/lzma.c | 20 ++++++++++++++++---- 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/payloads/libpayload/include/lzma.h b/payloads/libpayload/include/lzma.h index 818c16da1e..523bc8c99e 100644 --- a/payloads/libpayload/include/lzma.h +++ b/payloads/libpayload/include/lzma.h @@ -30,10 +30,18 @@ #ifndef _LZMA_H #define _LZMA_H -/* decompresses the data stream at src to dst, determining its length from +/* Decompresses the data stream at src to dst. The sizes of the source and + * destination buffers are in srcn and dstn. + * + * Returns the decompressed size, or 0 on error + */ +unsigned long ulzman(const unsigned char *src, unsigned long srcn, + unsigned char *dst, unsigned long dstn); + +/* Decompresses the data stream at src to dst, determining its length from * the data stream itself. * - * returns the decompressed size, or 0 on error + * Returns the decompressed size, or 0 on error */ unsigned long ulzma(const unsigned char *src, unsigned char *dst); diff --git a/payloads/libpayload/liblzma/lzma.c b/payloads/libpayload/liblzma/lzma.c index 0b97213070..af5555b3b0 100644 --- a/payloads/libpayload/liblzma/lzma.c +++ b/payloads/libpayload/liblzma/lzma.c @@ -14,9 +14,11 @@ #include #include "lzmadecode.c" -unsigned long ulzma(const unsigned char * src, unsigned char * dst) +unsigned long ulzman(const unsigned char *src, unsigned long srcn, + unsigned char *dst, unsigned long dstn) { unsigned char properties[LZMA_PROPERTIES_SIZE]; + const int data_offset = LZMA_PROPERTIES_SIZE + 8; UInt32 outSize; SizeT inProcessed; SizeT outProcessed; @@ -27,7 +29,12 @@ unsigned long ulzma(const unsigned char * src, unsigned char * dst) memcpy(properties, src, LZMA_PROPERTIES_SIZE); memcpy(&outSize, src + LZMA_PROPERTIES_SIZE, sizeof(outSize)); - if (LzmaDecodeProperties(&state.Properties, properties, LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) { + if (outSize > dstn) { + printf("lzma: Output truncated.\n"); + return 0; + } + if (LzmaDecodeProperties(&state.Properties, properties, + LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) { printf("lzma: Incorrect stream properties.\n"); return 0; } @@ -37,11 +44,16 @@ unsigned long ulzma(const unsigned char * src, unsigned char * dst) return 0; } state.Probs = (CProb *)scratchpad; - res = LzmaDecode(&state, src + LZMA_PROPERTIES_SIZE + 8, (SizeT)0xffffffff, &inProcessed, - dst, outSize, &outProcessed); + res = LzmaDecode(&state, src + data_offset, srcn - data_offset, + &inProcessed, dst, outSize, &outProcessed); if (res != 0) { printf("lzma: Decoding error = %d\n", res); return 0; } return outSize; } + +unsigned long ulzma(const unsigned char *src, unsigned char *dst) +{ + return ulzman(src, (unsigned long)(-1), dst, (unsigned long)(-1)); +}