| 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 |
| |