diff options
Diffstat (limited to 'meta/recipes-extended/libarchive/libarchive/CVE-2018-1000878.patch')
| -rw-r--r-- | meta/recipes-extended/libarchive/libarchive/CVE-2018-1000878.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/meta/recipes-extended/libarchive/libarchive/CVE-2018-1000878.patch b/meta/recipes-extended/libarchive/libarchive/CVE-2018-1000878.patch new file mode 100644 index 0000000000..7468fd3c93 --- /dev/null +++ b/meta/recipes-extended/libarchive/libarchive/CVE-2018-1000878.patch @@ -0,0 +1,79 @@ +CVE: CVE-2018-1000878 +Upstream-Status: Backport +Signed-off-by: Ross Burton <ross.burton@intel.com> + +From bfcfe6f04ed20db2504db8a254d1f40a1d84eb28 Mon Sep 17 00:00:00 2001 +From: Daniel Axtens <dja@axtens.net> +Date: Tue, 4 Dec 2018 00:55:22 +1100 +Subject: [PATCH] rar: file split across multi-part archives must match + +Fuzzing uncovered some UAF and memory overrun bugs where a file in a +single file archive reported that it was split across multiple +volumes. This was caused by ppmd7 operations calling +rar_br_fillup. This would invoke rar_read_ahead, which would in some +situations invoke archive_read_format_rar_read_header. That would +check the new file name against the old file name, and if they didn't +match up it would free the ppmd7 buffer and allocate a new +one. However, because the ppmd7 decoder wasn't actually done with the +buffer, it would continue to used the freed buffer. Both reads and +writes to the freed region can be observed. + +This is quite tricky to solve: once the buffer has been freed it is +too late, as the ppmd7 decoder functions almost universally assume +success - there's no way for ppmd_read to signal error, nor are there +good ways for functions like Range_Normalise to propagate them. So we +can't detect after the fact that we're in an invalid state - e.g. by +checking rar->cursor, we have to prevent ourselves from ever ending up +there. So, when we are in the dangerous part or rar_read_ahead that +assumes a valid split, we set a flag force read_header to either go +down the path for split files or bail. This means that the ppmd7 +decoder keeps a valid buffer and just runs out of data. + +Found with a combination of AFL, afl-rb and qsym. +--- + libarchive/archive_read_support_format_rar.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c +index 6f419c27..a8cc5c94 100644 +--- a/libarchive/archive_read_support_format_rar.c ++++ b/libarchive/archive_read_support_format_rar.c +@@ -258,6 +258,7 @@ struct rar + struct data_block_offsets *dbo; + unsigned int cursor; + unsigned int nodes; ++ char filename_must_match; + + /* LZSS members */ + struct huffman_code maincode; +@@ -1560,6 +1561,12 @@ read_header(struct archive_read *a, struct archive_entry *entry, + } + return ret; + } ++ else if (rar->filename_must_match) ++ { ++ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT, ++ "Mismatch of file parts split across multi-volume archive"); ++ return (ARCHIVE_FATAL); ++ } + + rar->filename_save = (char*)realloc(rar->filename_save, + filename_size + 1); +@@ -2933,12 +2940,14 @@ rar_read_ahead(struct archive_read *a, size_t min, ssize_t *avail) + else if (*avail == 0 && rar->main_flags & MHD_VOLUME && + rar->file_flags & FHD_SPLIT_AFTER) + { ++ rar->filename_must_match = 1; + ret = archive_read_format_rar_read_header(a, a->entry); + if (ret == (ARCHIVE_EOF)) + { + rar->has_endarc_header = 1; + ret = archive_read_format_rar_read_header(a, a->entry); + } ++ rar->filename_must_match = 0; + if (ret != (ARCHIVE_OK)) + return NULL; + return rar_read_ahead(a, min, avail); +-- +2.20.0 + |