Commit 2e857aaf authored Feb 11, 2018 by Jason Wang Committed by Greg Kroah-Hartman May 30, 2018

ptr_ring: prevent integer overflow when calculating size



[ Upstream commit 54e02162d4454a99227f520948bf4494c3d972d0 ]

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>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent a5338dbd

include/linux/ptr_ring.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -351,7 +351,7 @@ static inline void ptr_ring_consume_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 kcalloc(size, sizeof(void *), gfp);
		}