From: Jason Wang <jasowang@redhat.com>
Date: Fri, 9 Feb 2018 09:45:50 +0000 (+0800)
Subject: ptr_ring: try vmalloc() when kmalloc() fails
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b517942f5126c04fff8ff341cdd6a28b0a8de84f;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

ptr_ring: try vmalloc() when kmalloc() fails

commit 0bf7800f1799b5b1fd7d4f024e9ece53ac489011 upstream.

This patch switch to use kvmalloc_array() for using a vmalloc()
fallback to help in case kmalloc() fails.

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 bb515163bac3..35d125569e68 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -445,11 +445,14 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
 	__PTR_RING_PEEK_CALL_v; \
 })
 
+/* Not all gfp_t flags (besides GFP_KERNEL) are allowed. See
+ * documentation for vmalloc for which of them are legal.
+ */
 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);
+	return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO);
 }
 
 static inline void __ptr_ring_set_size(struct ptr_ring *r, int size)
@@ -582,7 +585,7 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp,
 	spin_unlock(&(r)->producer_lock);
 	spin_unlock_irqrestore(&(r)->consumer_lock, flags);
 
-	kfree(old);
+	kvfree(old);
 
 	return 0;
 }
@@ -622,7 +625,7 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings,
 	}
 
 	for (i = 0; i < nrings; ++i)
-		kfree(queues[i]);
+		kvfree(queues[i]);
 
 	kfree(queues);
 
@@ -630,7 +633,7 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings,
 
 nomem:
 	while (--i >= 0)
-		kfree(queues[i]);
+		kvfree(queues[i]);
 
 	kfree(queues);
 
@@ -645,7 +648,7 @@ static inline void ptr_ring_cleanup(struct ptr_ring *r, void (*destroy)(void *))
 	if (destroy)
 		while ((ptr = ptr_ring_consume(r)))
 			destroy(ptr);
-	kfree(r->queue);
+	kvfree(r->queue);
 }
 
 #endif /* _LINUX_PTR_RING_H  */