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Commit 2f36028c authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

IB/uverbs: Use u64_to_user_ptr() not a union 



The union approach will get the endianness wrong sometimes if the kernel's
pointer size is 32 bits resulting in EFAULTs when trying to copy to/from
user.

Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Reviewed-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 6c976c30

drivers/infiniband/core/uverbs_std_types.c

+2 −2
Original line number Diff line number Diff line
@@ -238,14 +238,14 @@ static void create_udata(struct uverbs_attr_bundle *ctx, 
		if (uverbs_attr_ptr_is_inline(uhw_in))

			udata->inbuf = &uhw_in->uattr->data;

		else

			udata->inbuf = uhw_in->ptr_attr.ptr;

			udata->inbuf = u64_to_user_ptr(uhw_in->ptr_attr.data);

	} else {

		udata->inbuf = NULL;

		udata->inlen = 0;

	}



	if (!IS_ERR(uhw_out)) {

		udata->outbuf = uhw_out->ptr_attr.ptr;

		udata->outbuf = u64_to_user_ptr(uhw_out->ptr_attr.data);

		udata->outlen = uhw_out->ptr_attr.len;

	} else {

		udata->outbuf = NULL;

include/rdma/uverbs_ioctl.h

+4 −6
Original line number Diff line number Diff line
@@ -276,10 +276,7 @@ struct uverbs_object_tree_def { 
 */



struct uverbs_ptr_attr {

	union {

	u64		data;

		void	__user *ptr;

	};

	u16		len;

	/* Combination of bits from enum UVERBS_ATTR_F_XXXX */

	u16		flags;
@@ -361,7 +358,7 @@ static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, 
		return PTR_ERR(attr);



	min_size = min_t(size_t, attr->ptr_attr.len, size);

	if (copy_to_user(attr->ptr_attr.ptr, from, min_size))

	if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))

		return -EFAULT;



	flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
@@ -396,7 +393,8 @@ static inline int _uverbs_copy_from(void *to, 


	if (uverbs_attr_ptr_is_inline(attr))

		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);

	else if (copy_from_user(to, attr->ptr_attr.ptr, attr->ptr_attr.len))

	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),

				attr->ptr_attr.len))

		return -EFAULT;



	return 0;