diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-devtools/json-c/json-c/0003-Fix-integer-overflows.patch')
-rw-r--r-- | meta-openbmc-mods/meta-common/recipes-devtools/json-c/json-c/0003-Fix-integer-overflows.patch | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-devtools/json-c/json-c/0003-Fix-integer-overflows.patch b/meta-openbmc-mods/meta-common/recipes-devtools/json-c/json-c/0003-Fix-integer-overflows.patch new file mode 100644 index 000000000..c94430210 --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-devtools/json-c/json-c/0003-Fix-integer-overflows.patch @@ -0,0 +1,90 @@ +From d07b91014986900a3a75f306d302e13e005e9d67 Mon Sep 17 00:00:00 2001 +From: Tobias Stoeckmann <tobias@stoeckmann.org> +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(-) + +diff --git a/linkhash.c b/linkhash.c +index f05cc38030..51e90b13a2 100644 +--- a/linkhash.c ++++ b/linkhash.c +@@ -580,9 +580,12 @@ int lh_table_insert_w_hash(struct lh_table *t, const void *k, const void *v, con + { + 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; + +diff --git a/printbuf.c b/printbuf.c +index 976c12dde5..00822fac4f 100644 +--- a/printbuf.c ++++ b/printbuf.c +@@ -15,6 +15,7 @@ + + #include "config.h" + ++#include <limits.h> + #include <stdio.h> + #include <stdlib.h> + #include <string.h> +@@ -65,10 +66,16 @@ static int printbuf_extend(struct printbuf *p, int min_size) + + if (p->size >= min_size) + return 0; +- +- new_size = p->size * 2; +- if (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", +@@ -83,6 +90,9 @@ static int printbuf_extend(struct printbuf *p, int min_size) + + 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; +@@ -100,6 +110,9 @@ int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len) + + 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) + { |