Re: invalid memory access in idna_to_ascii_8z

[Nikos Mavrogiannopoulos]

On Sat, Mar 28, 2015 at 12:51 PM, Nikos Mavrogiannopoulos
<address@hidden> wrote:
> Hello Simon,
>  Robert reported some invalid memory access in gnutls, and one I traced
> it back to libidn. A reproducer is attached. The reproducer uses strings
> on the heap because valgrind doesn't seem to detect such accesses on the
> stack.
> ==623== Invalid read of size 1
> ==623==    at 0x4E38E7F: g_utf8_to_ucs4_fast (nfkc.c:399)
> ==623==    by 0x4E38E7F: stringprep_utf8_to_ucs4 (nfkc.c:1023)
> ==623==    by 0x4E3A7DE: idna_to_ascii_8z (idna.c:578)
> ==623==    by 0x4005FD: main (in /home/nmav/cvs/gnutls/lib/a.out)
> ==623==  Address 0x541105f is 1 bytes after a block of size 30 alloc'd
> ==623==    at 0x4C28C20: malloc (vg_replace_malloc.c:296)
> ==623==    by 0x50E99D9: strdup (strdup.c:42)
> ==623==    by 0x4005E0: main (in /home/nmav/cvs/gnutls/lib/a.out)

The attached patches handle the reported issue. However, all functions
which use g_utf8_next_char() including g_utf8_strlen() are affected.

regards,
Nikos

0001-g_utf8_to_ucs4_fast-prevent-access-past-the-end-of-s.patch
Description: Text Data

0002-Added-a-check-for-invalid-encodings.patch
Description: Text Data