yara: fix several CVEs

CVE-2018-19974 CVE-2018-19975 CVE-2018-19976
2019-01-27 14:45:11 -06:00 · 2019-01-27 14:45:11 -06:00 · 599a1a2256
commit 599a1a2256
parent 054dad952c
2 changed files with 109 additions and 1 deletions
--- a/srcpkgs/yara/patches/CVE-2018-1997{4-6}.patch
+++ b/srcpkgs/yara/patches/CVE-2018-1997{4-6}.patch
@ -0,0 +1,108 @@
+From 0a3ede0125c8b88a020fa4c98df78f6eea7eb9ab Mon Sep 17 00:00:00 2001
+From: "Victor M. Alvarez" <plusvic@gmail.com>
+Date: Thu, 13 Dec 2018 12:23:09 +0100
+Subject: [PATCH] Fix issue #999 (#1001)
+
+* Add additional check in OP_COUNT for making sure that the string pointer is not a fake one.
+
+* Initialize scratch memory in order to avoid maliciously crafted YARA rules from reading values left in the stack.
+---
+ libyararena.c              | 10 +++++-----
+ libyarexec.c               | 11 +++++++++++
+ libyarinclude/yara/arena.h |  5 +++++
+ 3 files changed, 21 insertions(+), 5 deletions(-)
+
+diff --git libyara/arena.c libyara/arena.c
+index 34a374ef..805f6d70 100644
+--- libyara/arena.c
+++ libyararena.c
+@@ -109,7 +109,7 @@ static YR_ARENA_PAGE* _yr_arena_new_page(
+ 
+ 
+ //
+-// _yr_arena_page_for_address
+// yr_arena_page_for_address
+ //
+ // Returns the page within the arena where an address reside.
+ //
+@@ -122,7 +122,7 @@ static YR_ARENA_PAGE* _yr_arena_new_page(
+ //    resides.
+ //
+ 
+-static YR_ARENA_PAGE* _yr_arena_page_for_address(
+YR_ARENA_PAGE* yr_arena_page_for_address(
+     YR_ARENA* arena,
+     void* address)
+ {
+@@ -184,7 +184,7 @@ static int _yr_arena_make_ptr_relocatable(
+   // If the arena must be relocatable.
+   assert(arena->flags & ARENA_FLAGS_RELOCATABLE);
+ 
+-  page = _yr_arena_page_for_address(arena, base);
+  page = yr_arena_page_for_address(arena, base);
+ 
+   assert(page != NULL);
+ 
+@@ -361,7 +361,7 @@ void* yr_arena_next_address(
+ {
+   YR_ARENA_PAGE* page;
+ 
+-  page = _yr_arena_page_for_address(arena, address);
+  page = yr_arena_page_for_address(arena, address);
+ 
+   assert(page != NULL);
+ 
+@@ -482,7 +482,7 @@ int yr_arena_coalesce(
+ 
+     if (reloc_target != NULL)
+     {
+-      page = _yr_arena_page_for_address(arena, reloc_target);
+      page = yr_arena_page_for_address(arena, reloc_target);
+       assert(page != NULL);
+       *reloc_address = page->new_address + (reloc_target - page->address);
+     }
+diff --git libyara/exec.c libyara/exec.c
+index a0cf138d..9f0ba8fa 100644
+--- libyara/exec.c
+++ libyarexec.c
+@@ -246,6 +246,10 @@ int yr_execute_code(
+   start_time = yr_stopwatch_elapsed_us(&context->stopwatch);
+   #endif
+ 
+  #if PARANOID_EXEC
+  memset(mem, 0, MEM_SIZE * sizeof(mem[0]));
+  #endif
+
+   while(!stop)
+   {
+     opcode = *ip;
+@@ -779,6 +783,13 @@ int yr_execute_code(
+ 
+       case OP_COUNT:
+         pop(r1);
+
+        #if PARANOID_EXEC
+        // Make sure that the string pointer is within the rules arena.
+        if (yr_arena_page_for_address(context->rules->arena, r1.p) == NULL)
+          return ERROR_INTERNAL_FATAL_ERROR;
+        #endif
+
+         r1.i = r1.s->matches[tidx].count;
+         push(r1);
+         break;
+diff --git libyara/include/yara/arena.h libyara/include/yara/arena.h
+index 51f2d8cf..a42e594b 100644
+--- libyara/include/yara/arena.h
+++ libyarinclude/yara/arena.h
+@@ -101,6 +101,11 @@ void* yr_arena_base_address(
+     YR_ARENA* arena);
+ 
+ 
+YR_ARENA_PAGE* yr_arena_page_for_address(
+    YR_ARENA* arena,
+    void* address);
+
+
+ void* yr_arena_next_address(
+     YR_ARENA* arena,
+     void* address,
--- a/srcpkgs/yara/template
+++ b/srcpkgs/yara/template
@ -1,7 +1,7 @@
 # Template file for 'yara'
 pkgname=yara
 version=3.8.1
-revision=3
+revision=4
 build_style=gnu-configure
 configure_args="--enable-magic --enable-cuckoo"
 hostmakedepends="automake libtool"