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| author | Daniel Axtens <dja@axtens.net> | 2018-11-20 17:56:29 +1100 |
|---|---|---|
| committer | Daniel Axtens <dja@axtens.net> | 2018-12-11 13:58:11 +1100 |
| commit | 021efa522ad729ff0f5806c4ce53e4a6cc1daa31 (patch) | |
| tree | 86358b61eee3c36041e9f35824e85a322295de97 | |
| parent | 851adb9602f1acdb090067bb4f297cd609dfa28c (diff) | |
| download | libarchive-021efa522ad729ff0f5806c4ce53e4a6cc1daa31.tar.gz | |
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.
| -rw-r--r-- | libarchive/archive_read_support_format_rar.c | 5 |
1 files changed, 5 insertions, 0 deletions
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, |