[PATCH net] ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE

From: Jason Wang
Date: Wed Feb 07 2018 - 03:08:37 EST


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

Reported-by: syzbot+e4d4f9ddd4295539735d@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
include/linux/ptr_ring.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index 1883d61..4b862da 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -466,6 +466,8 @@ 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 > KMALLOC_MAX_SIZE)
+ return NULL;
return kcalloc(size, sizeof(void *), gfp);
}

--
2.7.4