ptr_ring: use kmalloc_array()

[ Upstream commit 81fbfe8adaf38d4f5a98c19bebfd41c5d6acaee8 ]

As found by syzkaller, malicious users can set whatever tx_queue_len
on a tun device and eventually crash the kernel.

Lets remove the ALIGN(XXX, SMP_CACHE_BYTES) thing since a small
ring buffer is not fast anyway.

Fixes: 2e0ab8ca83c1 ("ptr_ring: array based FIFO for pointers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@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 6c70444..b83507c 100644 (file)
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -340,9 +340,9 @@ static inline void *ptr_ring_consume_bh(struct ptr_ring *r)
        __PTR_RING_PEEK_CALL_v; \
 })
 
-static inline void **__ptr_ring_init_queue_alloc(int size, gfp_t gfp)
+static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
 {
-       return kzalloc(ALIGN(size * sizeof(void *), SMP_CACHE_BYTES), gfp);
+       return kcalloc(size, sizeof(void *), gfp);
 }
 
 static inline int ptr_ring_init(struct ptr_ring *r, int size, gfp_t gfp)
@@ -417,7 +417,8 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp,
  * In particular if you consume ring in interrupt or BH context, you must
  * disable interrupts/BH when doing so.
  */
-static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings,
+static inline int ptr_ring_resize_multiple(struct ptr_ring **rings,
+                                          unsigned int nrings,
                                           int size,
                                           gfp_t gfp, void (*destroy)(void *))
 {
@@ -425,7 +426,7 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings,
        void ***queues;
        int i;
 
-       queues = kmalloc(nrings * sizeof *queues, gfp);
+       queues = kmalloc_array(nrings, sizeof(*queues), gfp);
        if (!queues)
                goto noqueues;
 

diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h
index f4dfade..be8b902 100644 (file)
--- a/include/linux/skb_array.h
+++ b/include/linux/skb_array.h
@@ -162,7 +162,8 @@ static inline int skb_array_resize(struct skb_array *a, int size, gfp_t gfp)
 }
 
 static inline int skb_array_resize_multiple(struct skb_array **rings,
-                                           int nrings, int size, gfp_t gfp)
+                                           int nrings, unsigned int size,
+                                           gfp_t gfp)
 {
        BUILD_BUG_ON(offsetof(struct skb_array, ring));
        return ptr_ring_resize_multiple((struct ptr_ring **)rings,