[PATCH 24/32] IB/hfi1: Use mem_to_flex_dup() for struct tid_rb_node

Kees Cook
2022-05-04T01:58:41Z

As part of the work to perform bounds checking on all memcpy() uses,
replace the open-coded a deserialization of bytes out of memory into a
trailing flexible array by using a flex_array.h helper to perform the
allocation, bounds checking, and copying.

Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/infiniband/hw/hfi1/user_exp_rcv.c | 7 ++-----
drivers/infiniband/hw/hfi1/user_exp_rcv.h | 4 ++--
2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
index 186d30291260..f14846662ac9 100644
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -683,7 +683,7 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
{
int ret;
struct hfi1_ctxtdata *uctxt = fd->uctxt;
- struct tid_rb_node *node;
+ struct tid_rb_node *node = NULL;
struct hfi1_devdata *dd = uctxt->dd;
dma_addr_t phys;
struct page **pages = tbuf->pages + pageidx;
@@ -692,8 +692,7 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
* Allocate the node first so we can handle a potential
* failure before we've programmed anything.
*/
- node = kzalloc(struct_size(node, pages, npages), GFP_KERNEL);
- if (!node)
+ if (mem_to_flex_dup(&node, pages, npages, GFP_KERNEL))
return -ENOMEM;

phys = dma_map_single(&dd->pcidev->dev, __va(page_to_phys(pages[0])),
@@ -707,12 +706,10 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,

node->fdata = fd;
node->phys = page_to_phys(pages[0]);
- node->npages = npages;
node->rcventry = rcventry;
node->dma_addr = phys;
node->grp = grp;
node->freed = false;
- memcpy(node->pages, pages, flex_array_size(node, pages, npages));

if (fd->use_mn) {
ret = mmu_interval_notifier_insert(
diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.h b/drivers/infiniband/hw/hfi1/user_exp_rcv.h
index 8c53e416bf84..4be3446c4d25 100644
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.h
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.h
@@ -32,8 +32,8 @@ struct tid_rb_node {
u32 rcventry;
dma_addr_t dma_addr;
bool freed;
- unsigned int npages;
- struct page *pages[];
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(unsigned int, npages);
+ DECLARE_FLEX_ARRAY_ELEMENTS(struct page *, pages);
};

static inline int num_user_pages(unsigned long addr,
--
2.32.0