From bc0288b76816578f5aeccb2abd679f82bfc5738e Mon Sep 17 00:00:00 2001 From: Robert Marko Date: Tue, 12 May 2020 22:18:33 +0200 Subject: 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 --- .../patches/003-Fix-integer-overflows.patch | 86 ++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 package/libs/libjson-c/patches/003-Fix-integer-overflows.patch (limited to 'package/libs/libjson-c/patches/003-Fix-integer-overflows.patch') 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 0000000000..2fac62df59 --- /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) + { -- cgit v1.2.3