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 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
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-4.14 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 | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- 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_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;
info = kvmalloc(sz, GFP_KERNEL);
Patches currently in stable-queue which might be from dvyukov@google.com are
queue-4.14/kvm-x86-check-input-paging-mode-when-cs.l-is-set.patch queue-4.14/kvm-x86-fix-escape-of-guest-dr6-to-the-host.patch queue-4.14/blktrace-fix-unlocked-registration-of-tracepoints.patch queue-4.14/netfilter-x_tables-fix-int-overflow-in-xt_alloc_table_info.patch queue-4.14/netfilter-ipt_clusterip-fix-out-of-bounds-accesses-in-clusterip_tg_check.patch queue-4.14/kcov-detect-double-association-with-a-single-task.patch