Re: [PATCH] staging: vchiq_arm: Using copy_from_user() to copy data from userspace address
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2021-05-22 06:34:17
Also in:
linux-staging, lkml
On Sat, May 22, 2021 at 01:34:29PM +0800, Nguyen Dinh Phi wrote:
quoted hunk ↗ jump to hunk
This commit to fix the following sparse warning: incorrect type in assignment (different address spaces) expected void *[assigned] userdata got void [noderef] __user *userdata Signed-off-by: Nguyen Dinh Phi <redacted> --- .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c index afbf01b7364c..2a4fc599f977 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c@@ -960,7 +960,10 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance, current->pid); userdata = &waiter->bulk_waiter; } else { - userdata = args->userdata; + if (copy_from_user(userdata, args->userdata, sizeof(args->userdata))) {
The contents of userdata (local variable of type void *) is uninitialized at that point. Just what do you think that call of copy_from_user() would do? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel