| Message ID | 1457571383-25520-1-git-send-email-fw@strlen.de |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
On Thu, Mar 10, 2016 at 01:56:23AM +0100, Florian Westphal wrote: > Ben Hawkes says: > integer overflow in xt_alloc_table_info, which on 32-bit systems can > lead to small structure allocation and a copy_from_user based heap > corruption. Applied, thanks Florian. I have slightly mangled this patch, the second check suffices to catch this case for us. > Reported-by: Ben Hawkes <hawkes@google.com> > Signed-off-by: Florian Westphal <fw@strlen.de> > --- > net/netfilter/x_tables.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c > index c8a0b7d..17a9a9f 100644 > --- a/net/netfilter/x_tables.c > +++ b/net/netfilter/x_tables.c > @@ -659,6 +659,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) > struct xt_table_info *info = NULL; > size_t sz = sizeof(*info) + size; > > + if (sz < size || sz < sizeof(*info)) > + return NULL; So this will show up in the tree like this: if (sz < sizeof(*info)) return NULL; -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index c8a0b7d..17a9a9f 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -659,6 +659,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) struct xt_table_info *info = NULL; size_t sz = sizeof(*info) + size; + if (sz < size || sz < sizeof(*info)) + return NULL; + /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) return NULL;
Ben Hawkes says: integer overflow in xt_alloc_table_info, which on 32-bit systems can lead to small structure allocation and a copy_from_user based heap corruption. Reported-by: Ben Hawkes <hawkes@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> --- net/netfilter/x_tables.c | 3 +++ 1 file changed, 3 insertions(+)