Patch "netfilter: x_tables: fix int overflow in xt_alloc_table_info()" has been added to the 4.9-stable tree

Patch "netfilter: x_tables: fix int overflow in xt_alloc_table_info()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    netfilter: x_tables: fix int overflow in xt_alloc_table_info()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-x_tables-fix-int-overflow-in-xt_alloc_table_info.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 889c604fd0b5f6d3b8694ade229ee44124de1127 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 28 Dec 2017 09:48:54 +0100
Subject: netfilter: x_tables: fix int overflow in xt_alloc_table_info()

From: Dmitry Vyukov <dvyukov@google.com>

commit 889c604fd0b5f6d3b8694ade229ee44124de1127 upstream.

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>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/netfilter/x_tables.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -39,8 +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))
-
 struct compat_delta {
 	unsigned int offset; /* offset in kernel */
 	int delta; /* delta in 32bit user land */
@@ -952,7 +950,7 @@ struct xt_table_info *xt_alloc_table_inf
 		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;
 
 	if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))


Patches currently in stable-queue which might be from dvyukov@google.com are

queue-4.9/kvm-x86-fix-escape-of-guest-dr6-to-the-host.patch
queue-4.9/blktrace-fix-unlocked-registration-of-tracepoints.patch
queue-4.9/netfilter-x_tables-fix-int-overflow-in-xt_alloc_table_info.patch
queue-4.9/netfilter-ipt_clusterip-fix-out-of-bounds-accesses-in-clusterip_tg_check.patch
queue-4.9/kcov-detect-double-association-with-a-single-task.patch