vfio-user: vfio_user_device_io_set_irqs: prevent buffer overflow
This isn't in practise a problem since irq->argsz is not externally provided, it's a good hardening step nonetheless. Fixes: ca1add1696 ("vfio-user: implement VFIO_USER_DEVICE_GET/SET_IRQ*") Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Link: https://lore.kernel.org/qemu-devel/20260721122643.30985-9-thanos.makatos@nutanix.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
Thanos Makatos committed
Jul 21, 2026 at 12:27 UTC
bf10c11af515e7de6343a429f9d6b505c504d531
1 file changed
+4
-1
hw/vfio-user/device.c
+4
-1
@@ -293,7 +293,10 @@ static int vfio_user_device_io_set_irqs(VFIODevice *vbasedev,
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* Handle simple case
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*/
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if ((irq->flags & VFIO_IRQ_SET_DATA_EVENTFD) == 0) {
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- size = sizeof(VFIOUserHdr) + irq->argsz;
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+ if (__builtin_add_overflow(irq->argsz, sizeof(VFIOUserHdr), &size)) {
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+ error_printf("vfio_user_set_irqs argsz too large\n");
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+ return -E2BIG;
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+ }
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msgp = g_malloc0(size);
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vfio_user_request_msg(&msgp->hdr, VFIO_USER_DEVICE_SET_IRQS, size, 0);