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-rw-r--r--gnu/packages/patches/unzip-zipbomb-part3.patch112
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;
+
+