diff options
| -rw-r--r-- | package/utils/bzip2/Makefile | 2 | ||||
| -rw-r--r-- | package/utils/bzip2/patches/020-CVE-2019-12900.patch | 65 |
2 files changed, 66 insertions, 1 deletions
diff --git a/package/utils/bzip2/Makefile b/package/utils/bzip2/Makefile index ea2fc76833..0bf168c229 100644 --- a/package/utils/bzip2/Makefile +++ b/package/utils/bzip2/Makefile @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk PKG_NAME:=bzip2 PKG_VERSION:=1.0.6 -PKG_RELEASE:=4 +PKG_RELEASE:=5 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz PKG_SOURCE_URL:=http://www.bzip.org/$(PKG_VERSION) diff --git a/package/utils/bzip2/patches/020-CVE-2019-12900.patch b/package/utils/bzip2/patches/020-CVE-2019-12900.patch new file mode 100644 index 0000000000..3f08c789ea --- /dev/null +++ b/package/utils/bzip2/patches/020-CVE-2019-12900.patch @@ -0,0 +1,65 @@ +From 812a898b7622de90e98f103ff7fed0984e4548e4 Mon Sep 17 00:00:00 2001 +From: Mark Wielaard <mark@klomp.org> +Date: Wed, 3 Jul 2019 01:28:11 +0200 +Subject: [PATCH] Accept as many selectors as the file format allows. + +But ignore any larger than the theoretical maximum, BZ_MAX_SELECTORS. + +The theoretical maximum number of selectors depends on the maximum +blocksize (900000 bytes) and the number of symbols (50) that can be +encoded with a different Huffman tree. BZ_MAX_SELECTORS is 18002. + +But the bzip2 file format allows the number of selectors to be encoded +with 15 bits (because 18002 isn't a factor of 2 and doesn't fit in +14 bits). So the file format maximum is 32767 selectors. + +Some bzip2 encoders might actually have written out more selectors +than the theoretical maximum because they rounded up the number of +selectors to some convenient factor of 8. + +The extra 14766 selectors can never be validly used by the decompression +algorithm. So we can read them, but then discard them. + +This is effectively what was done (by accident) before we added a +check for nSelectors to be at most BZ_MAX_SELECTORS to mitigate +CVE-2019-12900. + +The extra selectors were written out after the array inside the +EState struct. But the struct has extra space allocated after the +selector arrays of 18060 bytes (which is larger than 14766). +All of which will be initialized later (so the overwrite of that +space with extra selector values would have been harmless). +--- + compress.c | 2 +- + decompress.c | 10 +++++++- + 2 files changed, 8 insertions(+), 2 deletions(-) + +--- a/compress.c ++++ b/compress.c +@@ -454,7 +454,7 @@ void sendMTFValues ( EState* s ) + + AssertH( nGroups < 8, 3002 ); + AssertH( nSelectors < 32768 && +- nSelectors <= (2 + (900000 / BZ_G_SIZE)), ++ nSelectors <= BZ_MAX_SELECTORS, + 3003 ); + + +--- a/decompress.c ++++ b/decompress.c +@@ -296,8 +296,14 @@ Int32 BZ2_decompress ( DState* s ) + j++; + if (j >= nGroups) RETURN(BZ_DATA_ERROR); + } +- s->selectorMtf[i] = j; ++ /* Having more than BZ_MAX_SELECTORS doesn't make much sense ++ since they will never be used, but some implementations might ++ "round up" the number of selectors, so just ignore those. */ ++ if (i < BZ_MAX_SELECTORS) ++ s->selectorMtf[i] = j; + } ++ if (nSelectors > BZ_MAX_SELECTORS) ++ nSelectors = BZ_MAX_SELECTORS; + + /*--- Undo the MTF values for the selectors. ---*/ + { |