From a1cb648d52f5b6d3f31184d9b6a7cbca628459b7 Mon Sep 17 00:00:00 2001 From: Wei-Cheng Pan Date: Mon, 29 Apr 2024 06:50:22 +0900 Subject: [PATCH] fix: OOB in rar delta filter (#2148) Ensure that `src` won't move ahead of `dst`, so `src` will not OOB. Since `dst` won't move in this function, and we are only increasing `src` position, this check should be enough. It should be safe to early return because this function does not allocate resources. --- libarchive/archive_read_support_format_rar.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c index 79669a8f..619ee81e 100644 --- a/libarchive/archive_read_support_format_rar.c +++ b/libarchive/archive_read_support_format_rar.c @@ -3612,7 +3612,15 @@ execute_filter_delta(struct rar_filter *filter, struct rar_virtual_machine *vm) { uint8_t lastbyte = 0; for (idx = i; idx < length; idx += numchannels) + { + /* + * The src block should not overlap with the dst block. + * If so it would be better to consider this archive is broken. + */ + if (src >= dst) + return 0; lastbyte = dst[idx] = lastbyte - *src++; + } } filter->filteredblockaddress = length; -- 2.46.2