Patch "ptr_ring: use kmalloc_array()" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    ptr_ring: use kmalloc_array()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ptr_ring-use-kmalloc_array.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Aug 24 17:44:02 PDT 2017
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 16 Aug 2017 10:36:47 -0700
Subject: ptr_ring: use kmalloc_array()

From: Eric Dumazet <edumazet@google.com>


[ 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>
---
 include/linux/ptr_ring.h  |    9 +++++----
 include/linux/skb_array.h |    3 ++-
 2 files changed, 7 insertions(+), 5 deletions(-)

--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -340,9 +340,9 @@ static inline void *ptr_ring_consume_bh(
 	__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
  * 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_multip
 	void ***queues;
 	int i;
 
-	queues = kmalloc(nrings * sizeof *queues, gfp);
+	queues = kmalloc_array(nrings, sizeof(*queues), gfp);
 	if (!queues)
 		goto noqueues;
 
--- a/include/linux/skb_array.h
+++ b/include/linux/skb_array.h
@@ -162,7 +162,8 @@ static inline int skb_array_resize(struc
 }
 
 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,


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.9/ipv4-fix-null-dereference-in-free_fib_info_rcu.patch
queue-4.9/tcp-when-rearming-rto-if-rto-time-is-in-past-then-fire-rto-asap.patch
queue-4.9/ipv4-better-ip_max_mtu-enforcement.patch
queue-4.9/dccp-defer-ccid_hc_tx_delete-at-dismantle-time.patch
queue-4.9/tipc-fix-use-after-free.patch
queue-4.9/af_key-do-not-use-gfp_kernel-in-atomic-contexts.patch
queue-4.9/ipv6-repair-fib6-tree-in-failure-case.patch
queue-4.9/dccp-purge-write-queue-in-dccp_destroy_sock.patch
queue-4.9/ipv6-reset-fn-rr_ptr-when-replacing-route.patch
queue-4.9/ptr_ring-use-kmalloc_array.patch
queue-4.9/net_sched-sfq-update-hierarchical-backlog-when-drop-packet.patch