From: Jason Wang <jasowang@redhat.com>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: mst@redhat.com, ebiggers3@gmail.com, Jason Wang <jasowang@redhat.com>
Subject: [PATCH net] ptr_ring: prevent integer overflow when calculating size
Date: Sun, 11 Feb 2018 11:28:12 +0800 [thread overview]
Message-ID: <1518319692-5421-1-git-send-email-jasowang@redhat.com> (raw)
Switch to use dividing to prevent integer overflow when size is too
big to calculate allocation size properly.
Reported-by: Eric Biggers <ebiggers3@gmail.com>
Fixes: 6e6e41c31122 ("ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
include/linux/ptr_ring.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index b884b77..e633522 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -469,7 +469,7 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
*/
static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
{
- if (size * sizeof(void *) > KMALLOC_MAX_SIZE)
+ if (size > KMALLOC_MAX_SIZE / sizeof(void *))
return NULL;
return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO);
}
--
2.7.4
next reply other threads:[~2018-02-11 3:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-11 3:28 Jason Wang [this message]
2018-02-11 22:02 ` [PATCH net] ptr_ring: prevent integer overflow when calculating size Michael S. Tsirkin
2018-02-12 3:34 ` David Miller
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