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CVE: CVE-2018-1000877
Upstream-Status: Backport
Signed-off-by: Ross Burton <ross.burton@intel.com>
From 021efa522ad729ff0f5806c4ce53e4a6cc1daa31 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Tue, 20 Nov 2018 17:56:29 +1100
Subject: [PATCH] Avoid a double-free when a window size of 0 is specified
new_size can be 0 with a malicious or corrupted RAR archive.
realloc(area, 0) is equivalent to free(area), so the region would
be free()d here and the free()d again in the cleanup function.
Found with a setup running AFL, afl-rb, and qsym.
---
libarchive/archive_read_support_format_rar.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
index 23452222..6f419c27 100644
--- a/libarchive/archive_read_support_format_rar.c
+++ b/libarchive/archive_read_support_format_rar.c
@@ -2300,6 +2300,11 @@ parse_codes(struct archive_read *a)
new_size = DICTIONARY_MAX_SIZE;
else
new_size = rar_fls((unsigned int)rar->unp_size) << 1;
+ if (new_size == 0) {
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Zero window size is invalid.");
+ return (ARCHIVE_FATAL);
+ }
new_window = realloc(rar->lzss.window, new_size);
if (new_window == NULL) {
archive_set_error(&a->archive, ENOMEM,
--
2.20.0
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