[Bug sanitizer/70541] New: unnoticed invalid dereference when using address sanitizer

["christof.warlich at siemens dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70541

            Bug ID: 70541
           Summary: unnoticed invalid dereference when using address
                    sanitizer
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: christof.warlich at siemens dot com
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
  Target Milestone: ---

The code below was ccompiled as:

$ gcc -fsanitize=address -fno-omit-frame-pointer -g sanitize.c

When executing the result, the sanitizer only complains about the
invalid dereference of the second printf statement, while the first
one goes unnoticed.

#include
#include

struct Simple {
    int value;
};
int f(struct Simple simple) {
    return simple.value;
}

int g(int value) {
    return value;
}

int main() {

    struct Simple *psimple = (struct Simple *) malloc(sizeof(struct Simple));
    psimple->value = 42;
    free(psimple);
    printf("%d\n", f(*psimple));

    int *pint = (int *) malloc(sizeof(int));
    *pint = 24;
    free(pint);
    printf("%d\n", g(*pint));

return 0;

}

$ gcc-5 -v
Using built-in specs.
COLLECT_GCC=gcc-5
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
5.3.0-3ubuntu1~14.04' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs
--enable-languages=c,ada,c++,java,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-5 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=gcc4-compatible --disable-libstdcxx-dual-abi
--enable-gnu-unique-object --disable-vtable-verify --enable-libmpx
--enable-plugin --with-system-zlib --disable-browser-plugin
--enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.3.0 20151204 (Ubuntu 5.3.0-3ubuntu1~14.04)