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ptr_ring: use kmalloc_array()

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[ 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>
This commit is contained in:
Eric Dumazet 2017-08-16 10:36:47 -07:00 committed by Greg Kroah-Hartman
parent 3c7af814de
commit 59af5b8769
2 changed files with 7 additions and 5 deletions

9
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;

3
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,