VMCI: check return value of get_user_pages_fast() for errors

In a couple of places in qp_host_get_user_memory(),
get_user_pages_fast() is called without properly checking for errors. If
e.g. -EFAULT is returned, this negative value will then be passed on to
qp_release_pages(), which expects a u64 as input.

Fix this by only calling qp_release_pages() when we have a positive
number returned.

Fixes: 06164d2b72 ("VMCI: queue pairs implementation.")
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Link: https://lore.kernel.org/r/20200825164522.412392-1-alex.dewar90@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alex Dewar 2020-08-25 17:45:18 +01:00 committed by Greg Kroah-Hartman
parent da0d6b3a53
commit 90ca6333fd

View File

@ -657,8 +657,9 @@ static int qp_host_get_user_memory(u64 produce_uva,
if (retval < (int)produce_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
retval);
qp_release_pages(produce_q->kernel_if->u.h.header_page,
retval, false);
if (retval > 0)
qp_release_pages(produce_q->kernel_if->u.h.header_page,
retval, false);
err = VMCI_ERROR_NO_MEM;
goto out;
}
@ -670,8 +671,9 @@ static int qp_host_get_user_memory(u64 produce_uva,
if (retval < (int)consume_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
retval);
qp_release_pages(consume_q->kernel_if->u.h.header_page,
retval, false);
if (retval > 0)
qp_release_pages(consume_q->kernel_if->u.h.header_page,
retval, false);
qp_release_pages(produce_q->kernel_if->u.h.header_page,
produce_q->kernel_if->num_pages, false);
err = VMCI_ERROR_NO_MEM;