On 03/31/2016 08:55 AM, Marcel Böhme wrote:
Hi,
This fixes the use-after-free detailed in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70481
There is a variable ksize storing the amount of allocated memory for the array
ktypevec. ksize being zero (0) indicates that some memory must be allocated
upon the first write. When more memory is needed, both ksize and the memory are
doubled during reallocation. At some point the memory for the array is freed
(in squangle_mop_up) but the value of ksize remains. Since ksize is not 0,
there is no indication that new memory must be allocated when there is another
write to the array.
The same holds for bsize and btypevec.
Best regards,
- Marcel
Index: libiberty/cplus-dem.c
===================================================================
--- libiberty/cplus-dem.c (revision 234607)
+++ libiberty/cplus-dem.c (working copy)
@@ -1237,11 +1237,13 @@ squangle_mop_up (struct work_stuff *work)
Thanks. I've just installed this patch, along with suitable tests from
70481 and 67394.
Jeff
commit 6e4dbbe6a1d6dd21e2ae87cabd1eae81312feac2
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Mar 31 17:20:53 2016 +0000
* cplus-dem.c (squangle_mop_up): Zero bsize/ksize after freeing
btypevec/ktypevec.
* testsuite/demangle-expected: Add coverage tests.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234645
138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index d11f4ce..b4054bd 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,10 @@
+2016-03-31 Mikhail Maltsev <malts...@gmail.com>
+ Marcel Bohme boehme.mar...@gmail.com
+
+ * cplus-dem.c (squangle_mop_up): Zero bsize/ksize after freeing
+ btypevec/ktypevec.
+ * testsuite/demangle-expected: Add coverage tests.
+
2016-01-27 Iain Buclaw <ibuc...@gdcproject.org>
* d-demangle.c (dlang_call_convention): Handle extern Objective-C
diff --git a/libiberty/cplus-dem.c b/libiberty/cplus-dem.c
index c68b981..7ab46dd 100644
--- a/libiberty/cplus-dem.c
+++ b/libiberty/cplus-dem.c
@@ -1237,11 +1237,13 @@ squangle_mop_up (struct work_stuff *work)
{
free ((char *) work -> btypevec);
work->btypevec = NULL;
+ work->bsize = 0;
}
if (work -> ktypevec != NULL)
{
free ((char *) work -> ktypevec);
work->ktypevec = NULL;
+ work->ksize = 0;
}
}
diff --git a/libiberty/testsuite/demangle-expected
b/libiberty/testsuite/demangle-expected
index aebf01b..e214ee5 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -4421,3 +4421,13 @@ void baz<int>(A<sizeof (foo((int)(), (floatcomplex
)00000000_00000000))>*)
--format=gnu-v3
_Z3fooI1FEN1XIXszdtcl1PclcvT__EEE5arrayEE4TypeEv
X<sizeof ((P(((F)())())).array)>::Type foo<F>()
+#
+# Tests a use-after-free problem
+
+_Q.__0
+::Q.(void)
+#
+# Tests a use-after-free problem
+
+_Q10-__9cafebabe.
+cafebabe.::-(void)
