busybox: add upstream patch for CVE-2021-28831

This commit is contained in:
Daniel Eyßer 2021-04-02 22:56:19 +02:00 committed by Érico Nogueira Rolim
parent a493736e6b
commit 777cf4e5c4
2 changed files with 59 additions and 2 deletions

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@ -0,0 +1,57 @@
From dbd3b883a891f076911d752f56f7a906d5650a17 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>
---
archival/libarchive/decompress_gunzip.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git archival/libarchive/decompress_gunzip.c archival/libarchive/decompress_gunzip.c
index 03049cc9b..e0520190a 100644
--- archival/libarchive/decompress_gunzip.c
+++ 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)
--
2.31.1

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@ -1,13 +1,13 @@
# Template file for 'busybox' # Template file for 'busybox'
pkgname=busybox pkgname=busybox
version=1.32.1 version=1.32.1
revision=1 revision=2
hostmakedepends="perl" hostmakedepends="perl"
checkdepends="tar which zip" checkdepends="tar which zip"
short_desc="Swiss Army Knife of Embedded Linux" short_desc="Swiss Army Knife of Embedded Linux"
maintainer="Cameron Nemo <cnemo@tutanota.com>" maintainer="Cameron Nemo <cnemo@tutanota.com>"
license="GPL-2.0-only" license="GPL-2.0-only"
homepage="http://www.busybox.net" homepage="https://www.busybox.net"
distfiles="${homepage}/downloads/busybox-${version}.tar.bz2" distfiles="${homepage}/downloads/busybox-${version}.tar.bz2"
checksum=9d57c4bd33974140fd4111260468af22856f12f5b5ef7c70c8d9b75c712a0dee checksum=9d57c4bd33974140fd4111260468af22856f12f5b5ef7c70c8d9b75c712a0dee