From: Jason Wang <jasowang@redhat.com>
Date: Fri, 9 Feb 2018 09:45:49 +0000 (+0800)
Subject: ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6688494804d87dcc8c936941f3f9969797af5419;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE

commit 6e6e41c3112276288ccaf80c70916779b84bb276 upstream.

To avoid slab to warn about exceeded size, fail early if queue
occupies more than KMALLOC_MAX_SIZE.

Reported-by: syzbot+e4d4f9ddd4295539735d@syzkaller.appspotmail.com
Fixes: 2e0ab8ca83c12 ("ptr_ring: array based FIFO for pointers")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index 6866df4f31b5..bb515163bac3 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -447,6 +447,8 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
 
 static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
 {
+	if (size * sizeof(void *) > KMALLOC_MAX_SIZE)
+		return NULL;
 	return kcalloc(size, sizeof(void *), gfp);
 }