| Message ID | 20171228084854.247843-1-dvyukov@google.com |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | netfilter: fix int overflow in xt_alloc_table_info() | expand |
On Thu, Dec 28, 2017 at 9:48 AM, Dmitry Vyukov <dvyukov@google.com> wrote: > syzkaller triggered OOM kills by passing ipt_replace.size = -1 > to IPT_SO_SET_REPLACE. The root cause is that SMP_ALIGN() in > xt_alloc_table_info() causes int overflow and the size check passes > when it should not. SMP_ALIGN() is no longer needed leftover. > > Remove SMP_ALIGN() call in xt_alloc_table_info(). > > Reported-by: syzbot+4396883fa8c4f64e0175@syzkaller.appspotmail.com > Signed-off-by: Dmitry Vyukov <dvyukov@google.com> > Cc: Pablo Neira Ayuso <pablo@netfilter.org> > Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> > Cc: Florian Westphal <fw@strlen.de> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: netfilter-devel@vger.kernel.org > Cc: coreteam@netfilter.org > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > net/netfilter/x_tables.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c > index 55802e97f906..e02a21549c99 100644 > --- a/net/netfilter/x_tables.c > +++ b/net/netfilter/x_tables.c > @@ -39,7 +39,6 @@ MODULE_LICENSE("GPL"); > MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); > MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); > > -#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) > #define XT_PCPU_BLOCK_SIZE 4096 > > struct compat_delta { > @@ -1000,7 +999,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) > return NULL; > > /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ > - if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) > + if ((size >> PAGE_SHIFT) + 2 > totalram_pages) > return NULL; > > info = kvmalloc(sz, GFP_KERNEL); Ping. Dave, will this go into net/net-next? -- 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
On Thu, Dec 28, 2017 at 09:48:54AM +0100, Dmitry Vyukov wrote: > syzkaller triggered OOM kills by passing ipt_replace.size = -1 > to IPT_SO_SET_REPLACE. The root cause is that SMP_ALIGN() in > xt_alloc_table_info() causes int overflow and the size check passes > when it should not. SMP_ALIGN() is no longer needed leftover. > > Remove SMP_ALIGN() call in xt_alloc_table_info(). Applied, thanks. -- 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 55802e97f906..e02a21549c99 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -39,7 +39,6 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); -#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) #define XT_PCPU_BLOCK_SIZE 4096 struct compat_delta { @@ -1000,7 +999,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) return NULL; /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ - if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) + if ((size >> PAGE_SHIFT) + 2 > totalram_pages) return NULL; info = kvmalloc(sz, GFP_KERNEL);
syzkaller triggered OOM kills by passing ipt_replace.size = -1 to IPT_SO_SET_REPLACE. The root cause is that SMP_ALIGN() in xt_alloc_table_info() causes int overflow and the size check passes when it should not. SMP_ALIGN() is no longer needed leftover. Remove SMP_ALIGN() call in xt_alloc_table_info(). Reported-by: syzbot+4396883fa8c4f64e0175@syzkaller.appspotmail.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: Florian Westphal <fw@strlen.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- net/netfilter/x_tables.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)