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| author | Hauke Mehrtens <hauke@hauke-m.de> | 2021-05-02 17:42:19 +0200 |
|---|---|---|
| committer | Hauke Mehrtens <hauke@hauke-m.de> | 2021-05-04 22:29:29 +0200 |
| commit | a641502849091feebf5d41c2eaa9ac89e59b8127 (patch) | |
| tree | 505d6282214a319ded546a17a6866d58653fd256 | |
| parent | 701d25b551144cacd5d7fd8024fd2e6c7c264b70 (diff) | |
| download | upstream-a641502849091feebf5d41c2eaa9ac89e59b8127.tar.gz upstream-a641502849091feebf5d41c2eaa9ac89e59b8127.tar.bz2 upstream-a641502849091feebf5d41c2eaa9ac89e59b8127.zip | |
busybox: backport fix for CVE-2021-28831
This backports a fix for the low priority CVE-2021-28831:
decompress_gunzip.c in BusyBox through 1.32.1 mishandles the error bit
on the huft_build result pointer, with a resultant invalid free or
segmentation fault, via malformed gzip data.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 13397b2b95b4800fb0a29c3d483fa280d10f0eb0)
| -rw-r--r-- | package/utils/busybox/Makefile | 2 | ||||
| -rw-r--r-- | package/utils/busybox/patches/005-backport-CVE-2021-28831.patch | 52 |
2 files changed, 53 insertions, 1 deletions
diff --git a/package/utils/busybox/Makefile b/package/utils/busybox/Makefile index 9df358ef78..58bc1e6795 100644 --- a/package/utils/busybox/Makefile +++ b/package/utils/busybox/Makefile @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk PKG_NAME:=busybox PKG_VERSION:=1.33.0 -PKG_RELEASE:=2 +PKG_RELEASE:=3 PKG_FLAGS:=essential PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2 diff --git a/package/utils/busybox/patches/005-backport-CVE-2021-28831.patch b/package/utils/busybox/patches/005-backport-CVE-2021-28831.patch new file mode 100644 index 0000000000..7637679a69 --- /dev/null +++ b/package/utils/busybox/patches/005-backport-CVE-2021-28831.patch @@ -0,0 +1,52 @@ +From f25d254dfd4243698c31a4f3153d4ac72aa9e9bd Mon Sep 17 00:00:00 2001 +From: Samuel Sapalski <samuel.sapalski@nokia.com> +Date: Wed, 3 Mar 2021 16:31:22 +0100 +Subject: 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(-) + +--- 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_PAR + * 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) |