Commit ae70890b authored Apr 29, 2024 by Alex Williamson Committed by Lin Yujun Apr 29, 2024

vfio/fsl-mc: Block calling interrupt handler without trigger

stable inclusion
from stable-v5.15.154
commit 250219c6a556f8c69c5910fca05a59037e24147d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E6TH
CVE: CVE-2024-26814

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=250219c6a556f8c69c5910fca05a59037e24147d



--------------------------------

[ Upstream commit 7447d911af699a15f8d050dfcb7c680a86f87012 ]

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@oss.nxp.com>
Cc:  <stable@vger.kernel.org>
Fixes: cc0ee20b ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-8-alex.williamson@redhat.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lin Yujun <linyujun809@huawei.com>

parent 76dda4fa

drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -142,13 +142,14 @@ 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, 1);

		} 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, 1);
		}

		return 0;