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

[Jason Wang]

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

Reported-by: syzbot+e4d4f9ddd42955397...@syzkaller.appspotmail.com
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
 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