From: Julian Seward <jseward@acm.org>
Date: Sat, 17 Nov 2007 02:05:57 +0000 (+0000)
Subject: Stack registration stuff: don't dereference NULL pointers (Eric
X-Git-Tag: svn/VALGRIND_3_3_0~120
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb12a8770d94fac2e06c5b6b0ba71ee47c39ef02;p=thirdparty%2Fvalgrind.git

Stack registration stuff: don't dereference NULL pointers (Eric
Sharkey, #150044).



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7171
---

diff --git a/coregrind/m_stacks.c b/coregrind/m_stacks.c
index 8400a6c8d6..90646595ac 100644
--- a/coregrind/m_stacks.c
+++ b/coregrind/m_stacks.c
@@ -154,7 +154,7 @@ void VG_(deregister_stack)(UWord id)
 
    VG_(debugLog)(2, "stacks", "deregister stack %lu\n", id);
 
-   if (current_stack->id == id) {
+   if (current_stack && current_stack->id == id) { 
       current_stack = NULL;
    }
 
@@ -209,7 +209,8 @@ void VG_(unknown_SP_update)( Addr old_SP, Addr new_SP )
    if (current_stack == NULL ||
        new_SP < current_stack->start || new_SP > current_stack->end) {
       Stack* new_stack = find_stack_by_addr(new_SP);
-      if (new_stack && new_stack->id != current_stack->id) {
+      if (new_stack 
+          && (current_stack == NULL || new_stack->id != current_stack->id)) { 
          /* The stack pointer is now in another stack.  Update the current
             stack information and return without doing anything else. */
          current_stack = new_stack;