From b23b1a195c089edb3289fbd564eae091363cfdf2 Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Thu, 31 Aug 2023 10:48:14 +0200 Subject: [PATCH] don't free memory that is still used after realloc() error (CVE-2020-22219) Resolves: CVE-2020-22219 --- flac-cve-2020-22219.patch | 182 ++++++++++++++++++++++++++++++++++++++ flac.spec | 3 + 2 files changed, 185 insertions(+) create mode 100644 flac-cve-2020-22219.patch diff --git a/flac-cve-2020-22219.patch b/flac-cve-2020-22219.patch new file mode 100644 index 0000000..cea7a92 --- /dev/null +++ b/flac-cve-2020-22219.patch @@ -0,0 +1,182 @@ +commit 21fe95ee828b0b9b944f6aa0bb02d24fbb981815 +Author: Martijn van Beurden +Date: Wed Aug 3 13:52:19 2022 +0200 + + Add and use _nofree variants of safe_realloc functions + + Parts of the code use realloc like + + x = safe_realloc(x, somesize); + + when this is the case, the safe_realloc variant used must free the + old memory block in case it fails, otherwise it will leak. However, + there are also instances in the code where handling is different: + + if (0 == (x = safe_realloc(y, somesize))) + return false + + in this case, y should not be freed, as y is not set to NULL we + could encounter double frees. Here the safe_realloc_nofree + functions are used. + +diff --git a/include/share/alloc.h b/include/share/alloc.h +index 9b53b010..74f444d6 100644 +--- a/include/share/alloc.h ++++ b/include/share/alloc.h +@@ -161,17 +161,30 @@ static inline void *safe_realloc_(void *ptr, size_t size) + free(oldptr); + return newptr; + } +-static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2) ++static inline void *safe_realloc_nofree_add_2op_(void *ptr, size_t size1, size_t size2) ++{ ++ size2 += size1; ++ if(size2 < size1) ++ return 0; ++ return realloc(ptr, size2); ++} ++ ++static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3) + { + size2 += size1; + if(size2 < size1) { + free(ptr); + return 0; + } +- return realloc(ptr, size2); ++ size3 += size2; ++ if(size3 < size2) { ++ free(ptr); ++ return 0; ++ } ++ return safe_realloc_(ptr, size3); + } + +-static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3) ++static inline void *safe_realloc_nofree_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3) + { + size2 += size1; + if(size2 < size1) +@@ -182,7 +195,7 @@ static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, + return realloc(ptr, size3); + } + +-static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4) ++static inline void *safe_realloc_nofree_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4) + { + size2 += size1; + if(size2 < size1) +@@ -207,6 +220,15 @@ static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2) + return safe_realloc_(ptr, size1*size2); + } + ++static inline void *safe_realloc_nofree_mul_2op_(void *ptr, size_t size1, size_t size2) ++{ ++ if(!size1 || !size2) ++ return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */ ++ if(size1 > SIZE_MAX / size2) ++ return 0; ++ return realloc(ptr, size1*size2); ++} ++ + /* size1 * (size2 + size3) */ + static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3) + { +@@ -220,4 +242,15 @@ static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, + return safe_realloc_mul_2op_(ptr, size1, size2); + } + ++/* size1 * (size2 + size3) */ ++static inline void *safe_realloc_nofree_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3) ++{ ++ if(!size1 || (!size2 && !size3)) ++ return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */ ++ size2 += size3; ++ if(size2 < size3) ++ return 0; ++ return safe_realloc_nofree_mul_2op_(ptr, size1, size2); ++} ++ + #endif +diff --git a/src/flac/encode.c b/src/flac/encode.c +index a7d1f7b2..b82ced76 100644 +--- a/src/flac/encode.c ++++ b/src/flac/encode.c +@@ -1734,10 +1734,10 @@ static void static_metadata_clear(static_metadata_t *m) + static FLAC__bool static_metadata_append(static_metadata_t *m, FLAC__StreamMetadata *d, FLAC__bool needs_delete) + { + void *x; +- if(0 == (x = safe_realloc_muladd2_(m->metadata, sizeof(*m->metadata), /*times (*/m->num_metadata, /*+*/1/*)*/))) ++ if(0 == (x = safe_realloc_nofree_muladd2_(m->metadata, sizeof(*m->metadata), /*times (*/m->num_metadata, /*+*/1/*)*/))) + return false; + m->metadata = (FLAC__StreamMetadata**)x; +- if(0 == (x = safe_realloc_muladd2_(m->needs_delete, sizeof(*m->needs_delete), /*times (*/m->num_metadata, /*+*/1/*)*/))) ++ if(0 == (x = safe_realloc_nofree_muladd2_(m->needs_delete, sizeof(*m->needs_delete), /*times (*/m->num_metadata, /*+*/1/*)*/))) + return false; + m->needs_delete = (FLAC__bool*)x; + m->metadata[m->num_metadata] = d; +diff --git a/src/flac/foreign_metadata.c b/src/flac/foreign_metadata.c +index 9a1fb96c..c86dff42 100644 +--- a/src/flac/foreign_metadata.c ++++ b/src/flac/foreign_metadata.c +@@ -74,7 +74,7 @@ static FLAC__bool copy_data_(FILE *fin, FILE *fout, size_t size, const char **er + + static FLAC__bool append_block_(foreign_metadata_t *fm, FLAC__off_t offset, FLAC__uint32 size, const char **error) + { +- foreign_block_t *fb = safe_realloc_muladd2_(fm->blocks, sizeof(foreign_block_t), /*times (*/fm->num_blocks, /*+*/1/*)*/); ++ foreign_block_t *fb = safe_realloc_nofree_muladd2_(fm->blocks, sizeof(foreign_block_t), /*times (*/fm->num_blocks, /*+*/1/*)*/); + if(fb) { + fb[fm->num_blocks].offset = offset; + fb[fm->num_blocks].size = size; +diff --git a/src/libFLAC/bitwriter.c b/src/libFLAC/bitwriter.c +index 79ab8649..8865a2f4 100644 +--- a/src/libFLAC/bitwriter.c ++++ b/src/libFLAC/bitwriter.c +@@ -133,7 +133,7 @@ FLAC__bool bitwriter_grow_(FLAC__BitWriter *bw, uint32_t bits_to_add) + FLAC__ASSERT(new_capacity > bw->capacity); + FLAC__ASSERT(new_capacity >= bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD)); + +- new_buffer = safe_realloc_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity); ++ new_buffer = safe_realloc_nofree_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity); + if(new_buffer == 0) + return false; + bw->buffer = new_buffer; +diff --git a/src/libFLAC/metadata_object.c b/src/libFLAC/metadata_object.c +index 7cc8ee9f..2c7da8db 100644 +--- a/src/libFLAC/metadata_object.c ++++ b/src/libFLAC/metadata_object.c +@@ -98,7 +98,7 @@ static FLAC__bool free_copy_bytes_(FLAC__byte **to, const FLAC__byte *from, uint + /* realloc() failure leaves entry unchanged */ + static FLAC__bool ensure_null_terminated_(FLAC__byte **entry, uint32_t length) + { +- FLAC__byte *x = safe_realloc_add_2op_(*entry, length, /*+*/1); ++ FLAC__byte *x = safe_realloc_nofree_add_2op_(*entry, length, /*+*/1); + if (x != NULL) { + x[length] = '\0'; + *entry = x; +diff --git a/src/plugin_common/tags.c b/src/plugin_common/tags.c +index e9227444..ffd846b6 100644 +--- a/src/plugin_common/tags.c ++++ b/src/plugin_common/tags.c +@@ -317,7 +317,7 @@ FLAC__bool FLAC_plugin__tags_add_tag_utf8(FLAC__StreamMetadata *tags, const char + const size_t value_len = strlen(value); + const size_t separator_len = strlen(separator); + FLAC__byte *new_entry; +- if(0 == (new_entry = safe_realloc_add_4op_(entry->entry, entry->length, /*+*/value_len, /*+*/separator_len, /*+*/1))) ++ if(0 == (new_entry = safe_realloc_nofree_add_4op_(entry->entry, entry->length, /*+*/value_len, /*+*/separator_len, /*+*/1))) + return false; + memcpy(new_entry+entry->length, separator, separator_len); + entry->length += separator_len; +diff --git a/src/share/utf8/iconvert.c b/src/share/utf8/iconvert.c +index 8ab53c10..876c06e8 100644 +--- a/src/share/utf8/iconvert.c ++++ b/src/share/utf8/iconvert.c +@@ -149,7 +149,7 @@ int iconvert(const char *fromcode, const char *tocode, + iconv_close(cd1); + return ret; + } +- newbuf = safe_realloc_add_2op_(utfbuf, (ob - utfbuf), /*+*/1); ++ newbuf = safe_realloc_nofree_add_2op_(utfbuf, (ob - utfbuf), /*+*/1); + if (!newbuf) + goto fail; + ob = (ob - utfbuf) + newbuf; diff --git a/flac.spec b/flac.spec index 9aa9576..6269261 100644 --- a/flac.spec +++ b/flac.spec @@ -28,6 +28,8 @@ BuildRequires: make Patch1: flac-cve-2020-0499.patch # handle end-of-stream when encoding with verification Patch2: flac-cve-2021-0561.patch +# don't free memory that is still used after realloc() error +Patch3: flac-cve-2020-22219.patch %description FLAC stands for Free Lossless Audio Codec. Grossly oversimplified, FLAC @@ -78,6 +80,7 @@ This is the input plugin for XMMS to be able to read FLAC files. %setup -q %patch1 -p1 -b .cve-2020-0499 %patch2 -p1 -b .cve-2021-0561 +%patch3 -p1 -b .cve-2020-22219 %build # use our libtool to avoid problems with RPATH