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IB/uverbs: Always use the attribute size provided by the user

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This fixes several bugs around the copy_to/from user path:
 - copy_to used the user provided size of the attribute
   and could copy data beyond the end of the kernel buffer into
   userspace.
 - copy_from didn't know the size of the kernel buffer and
   could have left kernel memory unexpectedly un-initialized.
 - copy_from did not use the user length to determine if the
   attribute data is inlined or not.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Matan Barak 2018-02-13 12:18:29 +02:00 committed by Jason Gunthorpe
parent 415bb699d7
commit 89d9e8d3f1
2 changed files with 31 additions and 9 deletions
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5
drivers/infiniband/core/uverbs_std_types.c
View File

@ -323,7 +323,8 @@ static int uverbs_create_cq_handler(struct ib_device *ib_dev,
cq->res.type = RDMA_RESTRACK_CQ;
rdma_restrack_add(&cq->res);
ret = uverbs_copy_to(attrs, CREATE_CQ_RESP_CQE, &cq->cqe);
ret = uverbs_copy_to(attrs, CREATE_CQ_RESP_CQE, &cq->cqe,
sizeof(cq->cqe));
if (ret)
goto err_cq;
@ -375,7 +376,7 @@ static int uverbs_destroy_cq_handler(struct ib_device *ib_dev,
resp.comp_events_reported = obj->comp_events_reported;
resp.async_events_reported = obj->async_events_reported;
return uverbs_copy_to(attrs, DESTROY_CQ_RESP, &resp);
return uverbs_copy_to(attrs, DESTROY_CQ_RESP, &resp, sizeof(resp));
}
static DECLARE_UVERBS_METHOD(

35
include/rdma/uverbs_ioctl.h
View File

@ -351,29 +351,50 @@ static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr
}
static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, const void *from)
size_t idx, const void *from, size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
u16 flags;
size_t min_size;
if (IS_ERR(attr))
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))
return -EFAULT;
flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
return (!copy_to_user(attr->ptr_attr.ptr, from, attr->ptr_attr.len) &&
!put_user(flags, &attr->uattr->flags)) ? 0 : -EFAULT;
if (put_user(flags, &attr->uattr->flags))
return -EFAULT;
return 0;
}
static inline int _uverbs_copy_from(void *to, size_t to_size,
static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
{
return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
}
static inline int _uverbs_copy_from(void *to,
const struct uverbs_attr_bundle *attrs_bundle,
size_t idx)
size_t idx,
size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
if (IS_ERR(attr))
return PTR_ERR(attr);
if (to_size <= sizeof(((struct ib_uverbs_attr *)0)->data))
/*
* Validation ensures attr->ptr_attr.len >= size. If the caller is
* using UVERBS_ATTR_SPEC_F_MIN_SZ then it must call copy_from with
* the right size.
*/
if (unlikely(size < attr->ptr_attr.len))
return -EINVAL;
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))
return -EFAULT;
@ -382,7 +403,7 @@ static inline int _uverbs_copy_from(void *to, size_t to_size,
}
#define uverbs_copy_from(to, attrs_bundle, idx) \
_uverbs_copy_from(to, sizeof(*(to)), attrs_bundle, idx)
_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
/* =================================================
* Definitions -> Specs infrastructure