From b4b5e9bf97970e0efc4a994de96066a92e3a9b8f Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Wed, 2 Dec 2020 15:46:34 +0100 Subject: Use 500 MB memory limit for xz/lzma decoding The buffers we feed in and read out are usually a couple kilobytes big so allowing lzma to use an unlimited amount of memory is easy & okay, but not needed and confuses memory checkers as it will cause lzma to malloc a huge chunk of memory (which it will never use). So lets just use a "big enough" value instead. In exchange we simplify the decoder calling as we were already using the auto-variant for xz, so we can just avoid the if-else and let liblzma decide what it decodes. --- apt-pkg/contrib/fileutl.cc | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) (limited to 'apt-pkg') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index e91c1acc3..091def3d4 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -1774,9 +1774,8 @@ public: #endif }; /*}}}*/ - -class APT_HIDDEN ZstdFileFdPrivate : public FileFdPrivate -{ /*{{{*/ +class APT_HIDDEN ZstdFileFdPrivate : public FileFdPrivate /*{{{*/ +{ #ifdef HAVE_ZSTD ZSTD_DStream *dctx; ZSTD_CStream *cctx; @@ -1986,7 +1985,7 @@ class APT_HIDDEN ZstdFileFdPrivate : public FileFdPrivate #endif }; /*}}}*/ -class APT_HIDDEN LzmaFileFdPrivate: public FileFdPrivate { /*{{{*/ +class APT_HIDDEN LzmaFileFdPrivate: public FileFdPrivate { /*{{{*/ #ifdef HAVE_LZMA struct LZMAFILE { FILE* file; @@ -2092,17 +2091,9 @@ public: } else { - uint64_t const memlimit = UINT64_MAX; - if (compressor.Name == "xz") - { - if (lzma_auto_decoder(&lzma->stream, memlimit, 0) != LZMA_OK) - return false; - } - else - { - if (lzma_alone_decoder(&lzma->stream, memlimit) != LZMA_OK) - return false; - } + uint64_t constexpr memlimit = 1024 * 1024 * 500; + if (lzma_auto_decoder(&lzma->stream, memlimit, 0) != LZMA_OK) + return false; lzma->compressing = false; } return true; -- cgit v1.2.3-70-g09d2