diff options
Diffstat (limited to 'gnu/packages/patches/unzip-zipbomb-part3.patch')
-rw-r--r-- | gnu/packages/patches/unzip-zipbomb-part3.patch | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/gnu/packages/patches/unzip-zipbomb-part3.patch b/gnu/packages/patches/unzip-zipbomb-part3.patch new file mode 100644 index 0000000000..3b8d67b773 --- /dev/null +++ b/gnu/packages/patches/unzip-zipbomb-part3.patch @@ -0,0 +1,112 @@ +From 6d351831be705cc26d897db44f878a978f4138fc Mon Sep 17 00:00:00 2001 +From: Mark Adler <madler@alumni.caltech.edu> +Date: Thu, 25 Jul 2019 20:43:17 -0700 +Subject: [PATCH] Do not raise a zip bomb alert for a misplaced central + directory. + +There is a zip-like file in the Firefox distribution, omni.ja, +which is a zip container with the central directory placed at the +start of the file instead of after the local entries as required +by the zip standard. This commit marks the actual location of the +central directory, as well as the end of central directory records, +as disallowed locations. This now permits such containers to not +raise a zip bomb alert, where in fact there are no overlaps. +--- + extract.c | 25 +++++++++++++++++++------ + process.c | 6 ++++++ + unzpriv.h | 10 ++++++++++ + 3 files changed, 35 insertions(+), 6 deletions(-) + +diff --git a/extract.c b/extract.c +index 0973a33..1b73cb0 100644 +--- a/extract.c ++++ b/extract.c +@@ -493,8 +493,11 @@ int extract_or_test_files(__G) /* return PK-type error code */ + } + #endif /* !SFX || SFX_EXDIR */ + +- /* One more: initialize cover structure for bomb detection. Start with a +- span that covers the central directory though the end of the file. */ ++ /* One more: initialize cover structure for bomb detection. Start with ++ spans that cover any extra bytes at the start, the central directory, ++ the end of central directory record (including the Zip64 end of central ++ directory locator, if present), and the Zip64 end of central directory ++ record, if present. */ + if (G.cover == NULL) { + G.cover = malloc(sizeof(cover_t)); + if (G.cover == NULL) { +@@ -506,15 +509,25 @@ int extract_or_test_files(__G) /* return PK-type error code */ + ((cover_t *)G.cover)->max = 0; + } + ((cover_t *)G.cover)->num = 0; +- if ((G.extra_bytes != 0 && +- cover_add((cover_t *)G.cover, 0, G.extra_bytes) != 0) || +- cover_add((cover_t *)G.cover, ++ if (cover_add((cover_t *)G.cover, + G.extra_bytes + G.ecrec.offset_start_central_directory, +- G.ziplen) != 0) { ++ G.extra_bytes + G.ecrec.offset_start_central_directory + ++ G.ecrec.size_central_directory) != 0) { + Info(slide, 0x401, ((char *)slide, + LoadFarString(NotEnoughMemCover))); + return PK_MEM; + } ++ if ((G.extra_bytes != 0 && ++ cover_add((cover_t *)G.cover, 0, G.extra_bytes) != 0) || ++ (G.ecrec.have_ecr64 && ++ cover_add((cover_t *)G.cover, G.ecrec.ec64_start, ++ G.ecrec.ec64_end) != 0) || ++ cover_add((cover_t *)G.cover, G.ecrec.ec_start, ++ G.ecrec.ec_end) != 0) { ++ Info(slide, 0x401, ((char *)slide, ++ LoadFarString(OverlappedComponents))); ++ return PK_BOMB; ++ } + + /*--------------------------------------------------------------------------- + The basic idea of this function is as follows. Since the central di- +diff --git a/process.c b/process.c +index d2e4dc3..d75d405 100644 +--- a/process.c ++++ b/process.c +@@ -1408,6 +1408,10 @@ static int find_ecrec64(__G__ searchlen) /* return PK-class error */ + + /* Now, we are (almost) sure that we have a Zip64 archive. */ + G.ecrec.have_ecr64 = 1; ++ G.ecrec.ec_start -= ECLOC64_SIZE+4; ++ G.ecrec.ec64_start = ecrec64_start_offset; ++ G.ecrec.ec64_end = ecrec64_start_offset + ++ 12 + makeint64(&byterec[ECREC64_LENGTH]); + + /* Update the "end-of-central-dir offset" for later checks. */ + G.real_ecrec_offset = ecrec64_start_offset; +@@ -1542,6 +1546,8 @@ static int find_ecrec(__G__ searchlen) /* return PK-class error */ + makelong(&byterec[OFFSET_START_CENTRAL_DIRECTORY]); + G.ecrec.zipfile_comment_length = + makeword(&byterec[ZIPFILE_COMMENT_LENGTH]); ++ G.ecrec.ec_start = G.real_ecrec_offset; ++ G.ecrec.ec_end = G.ecrec.ec_start + 22 + G.ecrec.zipfile_comment_length; + + /* Now, we have to read the archive comment, BEFORE the file pointer + is moved away backwards to seek for a Zip64 ECLOC64 structure. +diff --git a/unzpriv.h b/unzpriv.h +index dc9eff5..297b3c7 100644 +--- a/unzpriv.h ++++ b/unzpriv.h +@@ -2185,6 +2185,16 @@ typedef struct VMStimbuf { + int have_ecr64; /* valid Zip64 ecdir-record exists */ + int is_zip64_archive; /* Zip64 ecdir-record is mandatory */ + ush zipfile_comment_length; ++ zusz_t ec_start, ec_end; /* offsets of start and end of the ++ end of central directory record, ++ including if present the Zip64 ++ end of central directory locator, ++ which immediately precedes the ++ end of central directory record */ ++ zusz_t ec64_start, ec64_end; /* if have_ecr64 is true, then these ++ are the offsets of the start and ++ end of the Zip64 end of central ++ directory record */ + } ecdir_rec; + + |