From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Tue, 06 Oct 2020 13:47:48 +0000 Subject: [PATCH v2] staging: vchiq: Fix list_for_each exit tests Message-Id: <20201006134748.GA2076872@mwanda> List-Id: In-Reply-To: <20201001085650.GA1832570@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Nicolas Saenz Julienne Cc: Stefan Wahren , devel@driverdev.osuosl.org, Arnd Bergmann , Greg Kroah-Hartman , Marcelo Diop-Gonzalez , kernel-janitors@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-rpi-kernel@lists.infradead.org, Jamal Shareef After a list_for_each_entry() loop, the list iterator is always non-NULL so these conditions don't work. If the "waiter" is not found then this results in an out of bounds access. I have fixed it by introducing a new "found" variable. In one case, I used an else statement for readability. Fixes: 46e4b9ec4fa4 ("staging: vchiq_arm: use list_for_each_entry when accessing bulk_waiter_list") Signed-off-by: Dan Carpenter --- v2: rebase on latest linux-next .../vc04_services/interface/vchiq_arm/vchiq_arm.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) 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 590415561b73..e6a9aab66f4a 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -432,6 +432,7 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data, struct vchiq_service *service; enum vchiq_status status; struct bulk_waiter_node *waiter = NULL; + bool found = false; service = find_service_by_handle(handle); if (!service) @@ -445,12 +446,13 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data, list_for_each_entry(waiter, &instance->bulk_waiter_list, list) { if (waiter->pid = current->pid) { list_del(&waiter->list); + found = true; break; } } mutex_unlock(&instance->bulk_waiter_list_mutex); - if (waiter) { + if (found) { struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk; if (bulk) { @@ -467,9 +469,7 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data, spin_unlock(&bulk_waiter_spinlock); } } - } - - if (!waiter) { + } else { waiter = kzalloc(sizeof(struct bulk_waiter_node), GFP_KERNEL); if (!waiter) { vchiq_log_error(vchiq_core_log_level, @@ -952,6 +952,7 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance, { struct vchiq_service *service; struct bulk_waiter_node *waiter = NULL; + bool found = false; void *userdata; int status = 0; int ret; @@ -975,11 +976,12 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance, list) { if (waiter->pid = current->pid) { list_del(&waiter->list); + found = true; break; } } mutex_unlock(&instance->bulk_waiter_list_mutex); - if (!waiter) { + if (!found) { vchiq_log_error(vchiq_arm_log_level, "no bulk_waiter found for pid %d", current->pid); -- 2.28.0