From 81fbfe8adaf38d4f5a98c19bebfd41c5d6acaee8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 16 Aug 2017 10:36:47 -0700 Subject: [PATCH] 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: 2e0ab8ca83c1 ("ptr_ring: array based FIFO for pointers") Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Cc: Michael S. Tsirkin Cc: Jason Wang Signed-off-by: David S. Miller --- include/linux/ptr_ring.h | 9 +++++---- include/linux/skb_array.h | 3 ++- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index d8c97ec8a8e6..37b4bb2545b3 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -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; diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h index 35226cd4efb0..8621ffdeecbf 100644 --- a/include/linux/skb_array.h +++ b/include/linux/skb_array.h @@ -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, -- 2.20.1