From b55d79461d1f6aeaac03c7dae84481e5eb8bea4c Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Fri, 14 Dec 2018 20:34:30 +0200 Subject: [PATCH] xz: Fix a crash in progress indicator when in passthru mode. "xz -dcfv not_an_xz_file" crashed (all four options are required to trigger it). It caused xz to call lzma_get_progress(&strm, ...) when no coder was initialized in strm. In this situation strm.internal is NULL which leads to a crash in lzma_get_progress(). The bug was introduced when xz started using lzma_get_progress() to get progress info for multi-threaded compression, so the bug is present in versions 5.1.3alpha and higher. Thanks to Filip Palian for the bug report. --- src/xz/coder.c | 11 +++++++---- src/xz/message.c | 18 ++++++++++++++++-- src/xz/message.h | 3 ++- 3 files changed, 25 insertions(+), 7 deletions(-) diff --git a/src/xz/coder.c b/src/xz/coder.c index 3c6a01c..f36d1bf 100644 --- a/src/xz/coder.c +++ b/src/xz/coder.c @@ -902,16 +902,19 @@ coder_run(const char *filename) mytime_set_start_time(); // Initialize the progress indicator. + const bool is_passthru = init_ret + == CODER_INIT_PASSTHRU; const uint64_t in_size = pair->src_st.st_size <= 0 ? 0 : pair->src_st.st_size; - message_progress_start(&strm, in_size); + message_progress_start(&strm, + is_passthru, in_size); // Do the actual coding or passthru. - if (init_ret == CODER_INIT_NORMAL) - success = coder_normal(pair); - else + if (is_passthru) success = coder_passthru(pair); + else + success = coder_normal(pair); message_progress_end(success); } diff --git a/src/xz/message.c b/src/xz/message.c index 7e9ec53..f138af5 100644 --- a/src/xz/message.c +++ b/src/xz/message.c @@ -56,6 +56,11 @@ static bool progress_active = false; /// Pointer to lzma_stream used to do the encoding or decoding. static lzma_stream *progress_strm; +/// This is true if we are in passthru mode (not actually compressing or +/// decompressing) and thus cannot use lzma_get_progress(progress_strm, ...). +/// That is, we are using coder_passthru() in coder.c. +static bool progress_is_from_passthru; + /// Expected size of the input stream is needed to show completion percentage /// and estimate remaining time. static uint64_t expected_in_size; @@ -241,11 +246,12 @@ message_filename(const char *src_name) extern void -message_progress_start(lzma_stream *strm, uint64_t in_size) +message_progress_start(lzma_stream *strm, bool is_passthru, uint64_t in_size) { // Store the pointer to the lzma_stream used to do the coding. // It is needed to find out the position in the stream. progress_strm = strm; + progress_is_from_passthru = is_passthru; // Store the expected size of the file. If we aren't printing any // statistics, then is will be unused. But since it is possible @@ -507,7 +513,15 @@ progress_pos(uint64_t *in_pos, uint64_t *compressed_pos, uint64_t *uncompressed_pos) { uint64_t out_pos; - lzma_get_progress(progress_strm, in_pos, &out_pos); + if (progress_is_from_passthru) { + // In passthru mode the progress info is in total_in/out but + // the *progress_strm itself isn't initialized and thus we + // cannot use lzma_get_progress(). + *in_pos = progress_strm->total_in; + out_pos = progress_strm->total_out; + } else { + lzma_get_progress(progress_strm, in_pos, &out_pos); + } // It cannot have processed more input than it has been given. assert(*in_pos <= progress_strm->total_in); diff --git a/src/xz/message.h b/src/xz/message.h index 74599bd..894ac78 100644 --- a/src/xz/message.h +++ b/src/xz/message.h @@ -150,7 +150,8 @@ extern void message_filename(const char *src_name); /// \param strm Pointer to lzma_stream used for the coding. /// \param in_size Size of the input file, or zero if unknown. /// -extern void message_progress_start(lzma_stream *strm, uint64_t in_size); +extern void message_progress_start(lzma_stream *strm, + bool is_passthru, uint64_t in_size); /// Update the progress info if in verbose mode and enough time has passed