From bc0288b76816578f5aeccb2abd679f82bfc5738e Mon Sep 17 00:00:00 2001 From: Robert Marko Date: Tue, 12 May 2020 22:18:33 +0200 Subject: [PATCH] libjson-c: backport security fixes This backports upstream fixes for the out of bounds write vulnerability in json-c. It was reported and patches in this upstream PR: https://github.com/json-c/json-c/pull/592 Addresses CVE-2020-12762 Signed-off-by: Robert Marko Signed-off-by: Luka Perkov [bump PKG_RELEASE] Signed-off-by: Jo-Philipp Wich --- package/libs/libjson-c/Makefile | 2 +- ...list_del_idx-against-size_t-overflow.patch | 27 ++++++ ...Prevent-division-by-zero-in-linkhash.patch | 32 +++++++ .../patches/003-Fix-integer-overflows.patch | 86 +++++++++++++++++++ ...e-backwards-check-in-lh_table_insert.patch | 29 +++++++ 5 files changed, 175 insertions(+), 1 deletion(-) create mode 100644 package/libs/libjson-c/patches/001-Protect-array_list_del_idx-against-size_t-overflow.patch create mode 100644 package/libs/libjson-c/patches/002-Prevent-division-by-zero-in-linkhash.patch create mode 100644 package/libs/libjson-c/patches/003-Fix-integer-overflows.patch create mode 100644 package/libs/libjson-c/patches/004-Issue-599-Fix-the-backwards-check-in-lh_table_insert.patch diff --git a/package/libs/libjson-c/Makefile b/package/libs/libjson-c/Makefile index b61d99cc99f..f02518310a3 100644 --- a/package/libs/libjson-c/Makefile +++ b/package/libs/libjson-c/Makefile @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk PKG_NAME:=json-c PKG_VERSION:=0.13.1 -PKG_RELEASE:=1 +PKG_RELEASE:=2 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-nodoc.tar.gz PKG_SOURCE_URL:=https://s3.amazonaws.com/json-c_releases/releases/ diff --git a/package/libs/libjson-c/patches/001-Protect-array_list_del_idx-against-size_t-overflow.patch b/package/libs/libjson-c/patches/001-Protect-array_list_del_idx-against-size_t-overflow.patch new file mode 100644 index 00000000000..456fbf35ff2 --- /dev/null +++ b/package/libs/libjson-c/patches/001-Protect-array_list_del_idx-against-size_t-overflow.patch @@ -0,0 +1,27 @@ +From 099016b7e8d70a6d5dd814e788bba08d33d48426 Mon Sep 17 00:00:00 2001 +From: Tobias Stoeckmann +Date: Mon, 4 May 2020 19:41:16 +0200 +Subject: [PATCH 1/2] Protect array_list_del_idx against size_t overflow. + +If the assignment of stop overflows due to idx and count being +larger than SIZE_T_MAX in sum, out of boundary access could happen. + +It takes invalid usage of this function for this to happen, but +I decided to add this check so array_list_del_idx is as safe against +bad usage as the other arraylist functions. +--- + arraylist.c | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/arraylist.c ++++ b/arraylist.c +@@ -135,6 +135,9 @@ array_list_del_idx( struct array_list *a + { + size_t i, stop; + ++ /* Avoid overflow in calculation with large indices. */ ++ if (idx > SIZE_T_MAX - count) ++ return -1; + stop = idx + count; + if ( idx >= arr->length || stop > arr->length ) return -1; + for ( i = idx; i < stop; ++i ) { diff --git a/package/libs/libjson-c/patches/002-Prevent-division-by-zero-in-linkhash.patch b/package/libs/libjson-c/patches/002-Prevent-division-by-zero-in-linkhash.patch new file mode 100644 index 00000000000..d37fe5857bd --- /dev/null +++ b/package/libs/libjson-c/patches/002-Prevent-division-by-zero-in-linkhash.patch @@ -0,0 +1,32 @@ +From 77d935b7ae7871a1940cd827e850e6063044ec45 Mon Sep 17 00:00:00 2001 +From: Tobias Stoeckmann +Date: Mon, 4 May 2020 19:46:45 +0200 +Subject: [PATCH 2/2] Prevent division by zero in linkhash. + +If a linkhash with a size of zero is created, then modulo operations +are prone to division by zero operations. + +Purely protective measure against bad usage. +--- + linkhash.c | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/linkhash.c ++++ b/linkhash.c +@@ -12,6 +12,7 @@ + + #include "config.h" + ++#include + #include + #include + #include +@@ -498,6 +499,8 @@ struct lh_table* lh_table_new(int size, + int i; + struct lh_table *t; + ++ /* Allocate space for elements to avoid divisions by zero. */ ++ assert(size > 0); + t = (struct lh_table*)calloc(1, sizeof(struct lh_table)); + if (!t) + return NULL; diff --git a/package/libs/libjson-c/patches/003-Fix-integer-overflows.patch b/package/libs/libjson-c/patches/003-Fix-integer-overflows.patch new file mode 100644 index 00000000000..2fac62df593 --- /dev/null +++ b/package/libs/libjson-c/patches/003-Fix-integer-overflows.patch @@ -0,0 +1,86 @@ +From d07b91014986900a3a75f306d302e13e005e9d67 Mon Sep 17 00:00:00 2001 +From: Tobias Stoeckmann +Date: Mon, 4 May 2020 19:47:25 +0200 +Subject: [PATCH] Fix integer overflows. + +The data structures linkhash and printbuf are limited to 2 GB in size +due to a signed integer being used to track their current size. + +If too much data is added, then size variable can overflow, which is +an undefined behaviour in C programming language. + +Assuming that a signed int overflow just leads to a negative value, +like it happens on many sytems (Linux i686/amd64 with gcc), then +printbuf is vulnerable to an out of boundary write on 64 bit systems. +--- + linkhash.c | 7 +++++-- + printbuf.c | 19 ++++++++++++++++--- + 2 files changed, 21 insertions(+), 5 deletions(-) + +--- a/linkhash.c ++++ b/linkhash.c +@@ -579,9 +579,12 @@ int lh_table_insert_w_hash(struct lh_tab + { + unsigned long n; + +- if (t->count >= t->size * LH_LOAD_FACTOR) +- if (lh_table_resize(t, t->size * 2) != 0) ++ if (t->count >= t->size * LH_LOAD_FACTOR) { ++ /* Avoid signed integer overflow with large tables. */ ++ int new_size = INT_MAX / 2 < t->size ? t->size * 2 : INT_MAX; ++ if (t->size == INT_MAX || lh_table_resize(t, new_size) != 0) + return -1; ++ } + + n = h % t->size; + +--- a/printbuf.c ++++ b/printbuf.c +@@ -15,6 +15,7 @@ + + #include "config.h" + ++#include + #include + #include + #include +@@ -65,9 +66,16 @@ static int printbuf_extend(struct printb + if (p->size >= min_size) + return 0; + +- new_size = p->size * 2; +- if (new_size < min_size + 8) +- new_size = min_size + 8; ++ /* Prevent signed integer overflows with large buffers. */ ++ if (min_size > INT_MAX - 8) ++ return -1; ++ if (p->size > INT_MAX / 2) ++ new_size = min_size + 8; ++ else { ++ new_size = p->size * 2; ++ if (new_size < min_size + 8) ++ new_size = min_size + 8; ++ } + #ifdef PRINTBUF_DEBUG + MC_DEBUG("printbuf_memappend: realloc " + "bpos=%d min_size=%d old_size=%d new_size=%d\n", +@@ -82,6 +90,9 @@ static int printbuf_extend(struct printb + + int printbuf_memappend(struct printbuf *p, const char *buf, int size) + { ++ /* Prevent signed integer overflows with large buffers. */ ++ if (size > INT_MAX - p->bpos - 1) ++ return -1; + if (p->size <= p->bpos + size + 1) { + if (printbuf_extend(p, p->bpos + size + 1) < 0) + return -1; +@@ -98,6 +109,9 @@ int printbuf_memset(struct printbuf *pb, + + if (offset == -1) + offset = pb->bpos; ++ /* Prevent signed integer overflows with large buffers. */ ++ if (len > INT_MAX - offset) ++ return -1; + size_needed = offset + len; + if (pb->size < size_needed) + { diff --git a/package/libs/libjson-c/patches/004-Issue-599-Fix-the-backwards-check-in-lh_table_insert.patch b/package/libs/libjson-c/patches/004-Issue-599-Fix-the-backwards-check-in-lh_table_insert.patch new file mode 100644 index 00000000000..aed6918e708 --- /dev/null +++ b/package/libs/libjson-c/patches/004-Issue-599-Fix-the-backwards-check-in-lh_table_insert.patch @@ -0,0 +1,29 @@ +From 519dfe1591d85432986f9762d41d1a883198c157 Mon Sep 17 00:00:00 2001 +From: Eric Haszlakiewicz +Date: Sun, 10 May 2020 03:32:19 +0000 +Subject: [PATCH] Issue #599: Fix the backwards check in + lh_table_insert_w_hash() that was preventing adding more than 11 objects. Add + a test to check for this too. + +--- + linkhash.c | 2 +- + tests/test4.c | 29 +++++++++++++++++++++++++++++ + tests/test4.expected | 1 + + 3 files changed, 31 insertions(+), 1 deletion(-) + +diff --git a/linkhash.c b/linkhash.c +index 51e90b1..f930efd 100644 +--- a/linkhash.c ++++ b/linkhash.c +@@ -582,7 +582,7 @@ int lh_table_insert_w_hash(struct lh_table *t, const void *k, const void *v, con + + if (t->count >= t->size * LH_LOAD_FACTOR) { + /* Avoid signed integer overflow with large tables. */ +- int new_size = INT_MAX / 2 < t->size ? t->size * 2 : INT_MAX; ++ int new_size = (t->size > INT_MAX / 2) ? INT_MAX : (t->size * 2); + if (t->size == INT_MAX || lh_table_resize(t, new_size) != 0) + return -1; + } +-- +2.26.2 + -- 2.30.2