67 lines
2.4 KiB
Diff
67 lines
2.4 KiB
Diff
From 7f17c791dcfd8c0416e2cd2485b19410e47ef126 Mon Sep 17 00:00:00 2001
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From: Tim Kientzle <kientzle@acm.org>
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Date: Sun, 18 Sep 2016 18:14:58 -0700
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Subject: [PATCH] Issue 761: Heap overflow reading corrupted 7Zip files
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The sample file that demonstrated this had multiple 'EmptyStream'
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attributes. The first one ended up being used to calculate
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certain statistics, then was overwritten by the second which
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was incompatible with those statistics.
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The fix here is to reject any header with multiple EmptyStream
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attributes. While here, also reject headers with multiple
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EmptyFile, AntiFile, Name, or Attributes markers.
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---
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libarchive/archive_read_support_format_7zip.c | 10 ++++++++++
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1 file changed, 10 insertions(+)
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diff --git a/libarchive/archive_read_support_format_7zip.c b/libarchive/archive_read_support_format_7zip.c
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index 1dfe52b..c0a536c 100644
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--- a/libarchive/archive_read_support_format_7zip.c
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+++ b/libarchive/archive_read_support_format_7zip.c
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@@ -2431,6 +2431,8 @@ read_Header(struct archive_read *a, struct _7z_header_info *h,
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switch (type) {
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case kEmptyStream:
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+ if (h->emptyStreamBools != NULL)
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+ return (-1);
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h->emptyStreamBools = calloc((size_t)zip->numFiles,
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sizeof(*h->emptyStreamBools));
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if (h->emptyStreamBools == NULL)
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@@ -2451,6 +2453,8 @@ read_Header(struct archive_read *a, struct _7z_header_info *h,
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return (-1);
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break;
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}
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+ if (h->emptyFileBools != NULL)
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+ return (-1);
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h->emptyFileBools = calloc(empty_streams,
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sizeof(*h->emptyFileBools));
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if (h->emptyFileBools == NULL)
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@@ -2465,6 +2469,8 @@ read_Header(struct archive_read *a, struct _7z_header_info *h,
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return (-1);
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break;
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}
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+ if (h->antiBools != NULL)
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+ return (-1);
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h->antiBools = calloc(empty_streams,
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sizeof(*h->antiBools));
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if (h->antiBools == NULL)
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@@ -2491,6 +2497,8 @@ read_Header(struct archive_read *a, struct _7z_header_info *h,
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if ((ll & 1) || ll < zip->numFiles * 4)
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return (-1);
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+ if (zip->entry_names != NULL)
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+ return (-1);
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zip->entry_names = malloc(ll);
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if (zip->entry_names == NULL)
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return (-1);
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@@ -2543,6 +2551,8 @@ read_Header(struct archive_read *a, struct _7z_header_info *h,
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if ((p = header_bytes(a, 2)) == NULL)
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return (-1);
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allAreDefined = *p;
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+ if (h->attrBools != NULL)
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+ return (-1);
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h->attrBools = calloc((size_t)zip->numFiles,
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sizeof(*h->attrBools));
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if (h->attrBools == NULL)
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