Commit 46099d9900 for qemu.org

commit 46099d99005588b25eb07957cd9cdd688c4fc476
Author: Thomas Huth <thuth@redhat.com>
Date:   Fri Jul 31 13:33:52 2026 +0200

    hw/net/vmxnet3: Do not abort if guest provides bad interrupt numbers

    vmxnet3_validate_interrupts() currently aborts via hw_error() if
    the guest provided bad interrupt numbers. This should not happen,
    QEMU should rather refuse to activate the device in this case instead.
    Thus propagate the error to the callers to handle it more gracefully
    there.

    Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/539
    Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
    Signed-off-by: Thomas Huth <thuth@redhat.com>
    Message-ID: <20260731113352.189066-1-thuth@redhat.com>

diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index 8569484b2f..24c551a054 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -1336,32 +1336,46 @@ static bool vmxnet3_verify_intx(VMXNET3State *s, int intx)
         || intx == pci_get_byte(s->parent_obj.config + PCI_INTERRUPT_PIN) - 1;
 }

-static void vmxnet3_validate_interrupt_idx(bool is_msix, int idx)
+static bool vmxnet3_validate_irq_idx(const char *type, bool is_msix, int idx)
 {
     int max_ints = is_msix ? VMXNET3_MAX_INTRS : VMXNET3_MAX_NMSIX_INTRS;
+
     if (idx >= max_ints) {
-        hw_error("Bad interrupt index: %d\n", idx);
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "vmxnet3: Bad %s queue interrupt index: %d\n",
+                      type, idx);
+        return false;
     }
+
+    return true;
 }

-static void vmxnet3_validate_interrupts(VMXNET3State *s)
+static bool vmxnet3_validate_interrupts(VMXNET3State *s)
 {
     int i;

     VMW_CFPRN("Verifying event interrupt index (%d)", s->event_int_idx);
-    vmxnet3_validate_interrupt_idx(s->msix_used, s->event_int_idx);
+    if (!vmxnet3_validate_irq_idx("event", s->msix_used, s->event_int_idx)) {
+        return false;
+    }

     for (i = 0; i < s->txq_num; i++) {
         int idx = s->txq_descr[i].intr_idx;
         VMW_CFPRN("Verifying TX queue %d interrupt index (%d)", i, idx);
-        vmxnet3_validate_interrupt_idx(s->msix_used, idx);
+        if (!vmxnet3_validate_irq_idx("TX", s->msix_used, idx)) {
+            return false;
+        }
     }

     for (i = 0; i < s->rxq_num; i++) {
         int idx = s->rxq_descr[i].intr_idx;
         VMW_CFPRN("Verifying RX queue %d interrupt index (%d)", i, idx);
-        vmxnet3_validate_interrupt_idx(s->msix_used, idx);
+        if (!vmxnet3_validate_irq_idx("RX", s->msix_used, idx)) {
+            return false;
+        }
     }
+
+    return true;
 }

 static bool vmxnet3_validate_queues(VMXNET3State *s)
@@ -1554,7 +1568,9 @@ static void vmxnet3_activate_device(VMXNET3State *s)
                sizeof(s->rxq_descr[i].rxq_stats));
     }

-    vmxnet3_validate_interrupts(s);
+    if (!vmxnet3_validate_interrupts(s)) {
+        return;
+    }

     /* Make sure everything is in place before device activation */
     smp_wmb();
@@ -2392,7 +2408,9 @@ static int vmxnet3_post_load(void *opaque, int version_id)
     if (!vmxnet3_validate_queues(s)) {
         return -1;
     }
-    vmxnet3_validate_interrupts(s);
+    if (!vmxnet3_validate_interrupts(s)) {
+        return -1;
+    }

     return 0;
 }