ptr_ring: use kmalloc_array()

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: 2e0ab8ca83 ("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>
This commit is contained in:
Eric Dumazet 2017-08-16 10:36:47 -07:00 committed by David S. Miller
parent 120e9dabaf
commit 81fbfe8ada
2 changed files with 7 additions and 5 deletions

View File

@ -436,9 +436,9 @@ static inline int ptr_ring_consume_batched_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 void __ptr_ring_set_size(struct ptr_ring *r, int size)
@ -582,7 +582,8 @@ 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 *))
{
@ -590,7 +591,7 @@ 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;

View File

@ -193,7 +193,8 @@ 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,