linux-kernel - [PATCH v2 7/7] vfio/fsl-mc: Block calling interrupt handler without trigger

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240308230557.805580-8-alex.williamson@redhat.com>
Date: Fri,  8 Mar 2024 16:05:28 -0700
From: Alex Williamson <alex.williamson@...hat.com>
To: alex.williamson@...hat.com
Cc: kvm@...r.kernel.org,
	eric.auger@...hat.com,
	clg@...hat.com,
	reinette.chatre@...el.com,
	linux-kernel@...r.kernel.org,
	kevin.tian@...el.com,
	diana.craciun@....nxp.com,
	stable@...r.kernel.org
Subject: [PATCH v2 7/7] vfio/fsl-mc: Block calling interrupt handler without trigger

The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
initially NULL and may become NULL if the user sets the trigger
eventfd to -1.  The interrupt handler itself is guaranteed that
trigger is always valid between request_irq() and free_irq(), but
the loopback testing mechanisms to invoke the handler function
need to test the trigger.  The triggering and setting ioctl paths
both make use of igate and are therefore mutually exclusive.

The vfio-fsl-mc driver does not make use of irqfds, nor does it
support any sort of masking operations, therefore unlike vfio-pci
and vfio-platform, the flow can remain essentially unchanged.

Cc: Diana Craciun <diana.craciun@....nxp.com>
Cc: stable@...r.kernel.org
Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd")
Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
index d62fbfff20b8..82b2afa9b7e3 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
@@ -141,13 +141,14 @@ static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
 	irq = &vdev->mc_irqs[index];
 
 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
-		vfio_fsl_mc_irq_handler(hwirq, irq);
+		if (irq->trigger)
+			eventfd_signal(irq->trigger);
 
 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 		u8 trigger = *(u8 *)data;
 
-		if (trigger)
-			vfio_fsl_mc_irq_handler(hwirq, irq);
+		if (trigger && irq->trigger)
+			eventfd_signal(irq->trigger);
 	}
 
 	return 0;
-- 
2.44.0