busybox: fix CVE-2021-28831

Backport patch to fix CVE-2021-28831.

(From OE-Core rev: e579dbd9a6b2472ca90f411c0b594da9e38c9aca)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Chen Qi 2021-04-07 21:55:18 -07:00 committed by Richard Purdie
parent cf80f79422
commit bbec2f3f29
2 changed files with 60 additions and 1 deletions

View File

@ -0,0 +1,58 @@
From fe791386ebc270219ca00406c9fdadc5130b64ee Mon Sep 17 00:00:00 2001
From: Samuel Sapalski <samuel.sapalski@nokia.com>
Date: Wed, 3 Mar 2021 16:31:22 +0100
Subject: [PATCH] decompress_gunzip: Fix DoS if gzip is corrupt
On certain corrupt gzip files, huft_build will set the error bit on
the result pointer. If afterwards abort_unzip is called huft_free
might run into a segmentation fault or an invalid pointer to
free(p).
In order to mitigate this, we check in huft_free if the error bit
is set and clear it before the linked list is freed.
Signed-off-by: Samuel Sapalski <samuel.sapalski@nokia.com>
Signed-off-by: Peter Kaestle <peter.kaestle@nokia.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Upstream-Status: Backport
CVE: CVE-2021-28831
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
archival/libarchive/decompress_gunzip.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/archival/libarchive/decompress_gunzip.c b/archival/libarchive/decompress_gunzip.c
index eb3b64930..e93cd5005 100644
--- a/archival/libarchive/decompress_gunzip.c
+++ b/archival/libarchive/decompress_gunzip.c
@@ -220,10 +220,20 @@ static const uint8_t border[] ALIGN1 = {
* each table.
* t: table to free
*/
+#define BAD_HUFT(p) ((uintptr_t)(p) & 1)
+#define ERR_RET ((huft_t*)(uintptr_t)1)
static void huft_free(huft_t *p)
{
huft_t *q;
+ /*
+ * If 'p' has the error bit set we have to clear it, otherwise we might run
+ * into a segmentation fault or an invalid pointer to free(p)
+ */
+ if (BAD_HUFT(p)) {
+ p = (huft_t*)((uintptr_t)(p) ^ (uintptr_t)(ERR_RET));
+ }
+
/* Go through linked list, freeing from the malloced (t[-1]) address. */
while (p) {
q = (--p)->v.t;
@@ -289,8 +299,6 @@ static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current
* or a valid pointer to a Huffman table, ORed with 0x1 if incompete table
* is given: "fixed inflate" decoder feeds us such data.
*/
-#define BAD_HUFT(p) ((uintptr_t)(p) & 1)
-#define ERR_RET ((huft_t*)(uintptr_t)1)
static huft_t* huft_build(const unsigned *b, const unsigned n,
const unsigned s, const struct cp_ext *cp_ext,
unsigned *m)

View File

@ -46,7 +46,8 @@ SRC_URI = "https://busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
file://0001-sysctl-ignore-EIO-of-stable_secret-below-proc-sys-ne.patch \
file://rev.cfg \
file://pgrep.cfg \
"
file://0001-decompress_gunzip-Fix-DoS-if-gzip-is-corrupt.patch \
"
SRC_URI_append_libc-musl = " file://musl.cfg "
SRC_URI[tarball.sha256sum] = "d568681c91a85edc6710770cebc1e80e042ad74d305b5c2e6d57a5f3de3b8fbd"