120 lines
4.6 KiB
Diff
120 lines
4.6 KiB
Diff
From eac15e252010c1189a5c0f461364dbe2cd2a68b1 Mon Sep 17 00:00:00 2001
|
|
From: "Dustin L. Howett" <dustin@howett.net>
|
|
Date: Thu, 9 May 2024 18:59:17 -0500
|
|
Subject: [PATCH] rar4 reader: protect copy_from_lzss_window_to_unp() (#2172)
|
|
|
|
copy_from_lzss_window_to_unp unnecessarily took an `int` parameter where
|
|
both of its callers were holding a `size_t`.
|
|
|
|
A lzss opcode chain could be constructed that resulted in a negative
|
|
copy length, which when passed into memcpy would result in a very, very
|
|
large positive number.
|
|
|
|
Switching copy_from_lzss_window_to_unp to take a `size_t` allows it to
|
|
properly bounds-check length.
|
|
|
|
In addition, this patch also ensures that `length` is not itself larger
|
|
than the destination buffer.
|
|
|
|
Security: CVE-2024-20696
|
|
|
|
Reference:https://github.com/libarchive/libarchive/commit/eac15e252010c1189a5c0f461364dbe2cd2a68b1
|
|
Conflict:copy_from_lzss_window_to_unp() -> copy_from_lzss_window();adapt context
|
|
---
|
|
libarchive/archive_read_support_format_rar.c | 28 +++++++++++++-------
|
|
1 file changed, 18 insertions(+), 10 deletions(-)
|
|
|
|
diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
|
|
index c2666b2..512f5a6 100644
|
|
--- a/libarchive/archive_read_support_format_rar.c
|
|
+++ b/libarchive/archive_read_support_format_rar.c
|
|
@@ -358,7 +358,7 @@ static int make_table_recurse(struct archive_read *, struct huffman_code *, int,
|
|
struct huffman_table_entry *, int, int);
|
|
static int64_t expand(struct archive_read *, int64_t);
|
|
static int copy_from_lzss_window(struct archive_read *, const void **,
|
|
- int64_t, int);
|
|
+ int64_t, size_t);
|
|
static const void *rar_read_ahead(struct archive_read *, size_t, ssize_t *);
|
|
|
|
/*
|
|
@@ -1936,7 +1936,7 @@ read_data_compressed(struct archive_read *a, const void **buff, size_t *size,
|
|
bs = rar->unp_buffer_size - rar->unp_offset;
|
|
else
|
|
bs = (size_t)rar->bytes_uncopied;
|
|
- ret = copy_from_lzss_window(a, buff, rar->offset, (int)bs);
|
|
+ ret = copy_from_lzss_window(a, buff, rar->offset, bs);
|
|
if (ret != ARCHIVE_OK)
|
|
return (ret);
|
|
rar->offset += bs;
|
|
@@ -2065,7 +2065,7 @@ read_data_compressed(struct archive_read *a, const void **buff, size_t *size,
|
|
bs = rar->unp_buffer_size - rar->unp_offset;
|
|
else
|
|
bs = (size_t)rar->bytes_uncopied;
|
|
- ret = copy_from_lzss_window(a, buff, rar->offset, (int)bs);
|
|
+ ret = copy_from_lzss_window(a, buff, rar->offset, bs);
|
|
if (ret != ARCHIVE_OK)
|
|
return (ret);
|
|
rar->offset += bs;
|
|
@@ -2923,11 +2923,16 @@ bad_data:
|
|
|
|
static int
|
|
copy_from_lzss_window(struct archive_read *a, const void **buffer,
|
|
- int64_t startpos, int length)
|
|
+ int64_t startpos, size_t length)
|
|
{
|
|
int windowoffs, firstpart;
|
|
struct rar *rar = (struct rar *)(a->format->data);
|
|
|
|
+ if (length > rar->unp_buffer_size)
|
|
+ {
|
|
+ goto fatal;
|
|
+ }
|
|
+
|
|
if (!rar->unp_buffer)
|
|
{
|
|
if ((rar->unp_buffer = malloc(rar->unp_buffer_size)) == NULL)
|
|
@@ -2939,17 +2944,17 @@ copy_from_lzss_window(struct archive_read *a, const void **buffer,
|
|
}
|
|
|
|
windowoffs = lzss_offset_for_position(&rar->lzss, startpos);
|
|
- if(windowoffs + length <= lzss_size(&rar->lzss)) {
|
|
+ if(windowoffs + length <= (size_t)lzss_size(&rar->lzss)) {
|
|
memcpy(&rar->unp_buffer[rar->unp_offset], &rar->lzss.window[windowoffs],
|
|
length);
|
|
- } else if (length <= lzss_size(&rar->lzss)) {
|
|
+ } else if (length <= (size_t)lzss_size(&rar->lzss)) {
|
|
firstpart = lzss_size(&rar->lzss) - windowoffs;
|
|
if (firstpart < 0) {
|
|
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
|
|
"Bad RAR file data");
|
|
return (ARCHIVE_FATAL);
|
|
}
|
|
- if (firstpart < length) {
|
|
+ if ((size_t)firstpart < length) {
|
|
memcpy(&rar->unp_buffer[rar->unp_offset],
|
|
&rar->lzss.window[windowoffs], firstpart);
|
|
memcpy(&rar->unp_buffer[rar->unp_offset + firstpart],
|
|
@@ -2959,9 +2964,7 @@ copy_from_lzss_window(struct archive_read *a, const void **buffer,
|
|
&rar->lzss.window[windowoffs], length);
|
|
}
|
|
} else {
|
|
- archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
|
|
- "Bad RAR file data");
|
|
- return (ARCHIVE_FATAL);
|
|
+ goto fatal;
|
|
}
|
|
rar->unp_offset += length;
|
|
if (rar->unp_offset >= rar->unp_buffer_size)
|
|
@@ -2969,6 +2972,11 @@ copy_from_lzss_window(struct archive_read *a, const void **buffer,
|
|
else
|
|
*buffer = NULL;
|
|
return (ARCHIVE_OK);
|
|
+
|
|
+fatal:
|
|
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
|
|
+ "Bad RAR file data");
|
|
+ return (ARCHIVE_FATAL);
|
|
}
|
|
|
|
static const void *
|