net: mana: Fix accessing freed irq affinity_hint

After calling irq_set_affinity_and_hint(), the cpumask pointer is
saved in desc->affinity_hint, and will be used later when reading
/proc/irq/<num>/affinity_hint. So the cpumask variable needs to be
persistent. Otherwise, we are accessing freed memory when reading
the affinity_hint file.

Also, need to clear affinity_hint before free_irq(), otherwise there
is a one-time warning and stack trace during module unloading:

 [  243.948687] WARNING: CPU: 10 PID: 1589 at kernel/irq/manage.c:1913 free_irq+0x318/0x360
 ...
 [  243.948753] Call Trace:
 [  243.948754]  <TASK>
 [  243.948760]  mana_gd_remove_irqs+0x78/0xc0 [mana]
 [  243.948767]  mana_gd_remove+0x3e/0x80 [mana]
 [  243.948773]  pci_device_remove+0x3d/0xb0
 [  243.948778]  device_remove+0x46/0x70
 [  243.948782]  device_release_driver_internal+0x1fe/0x280
 [  243.948785]  driver_detach+0x4e/0xa0
 [  243.948787]  bus_remove_driver+0x70/0xf0
 [  243.948789]  driver_unregister+0x35/0x60
 [  243.948792]  pci_unregister_driver+0x44/0x90
 [  243.948794]  mana_driver_exit+0x14/0x3fe [mana]
 [  243.948800]  __do_sys_delete_module.constprop.0+0x185/0x2f0

To fix the bug, use the persistent mask, cpumask_of(cpu#), and set
affinity_hint to NULL before freeing the IRQ, as required by free_irq().

Cc: stable@vger.kernel.org
Fixes: 71fa6887eeca ("net: mana: Assign interrupts to CPUs based on NUMA nodes")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/1675718929-19565-1-git-send-email-haiyangz@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index b144f2237748e7d9a2d052010cf57a59676edd2f..f9b8f372ec8a744e246b1f43fa513e9c115c5f6a 100644 (file)
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1217,9 +1217,7 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
        unsigned int max_queues_per_port = num_online_cpus();
        struct gdma_context *gc = pci_get_drvdata(pdev);
        struct gdma_irq_context *gic;
-       unsigned int max_irqs;
-       u16 *cpus;
-       cpumask_var_t req_mask;
+       unsigned int max_irqs, cpu;
        int nvec, irq;
        int err, i = 0, j;
 
@@ -1240,21 +1238,7 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
                goto free_irq_vector;
        }
 
-       if (!zalloc_cpumask_var(&req_mask, GFP_KERNEL)) {
-               err = -ENOMEM;
-               goto free_irq;
-       }
-
-       cpus = kcalloc(nvec, sizeof(*cpus), GFP_KERNEL);
-       if (!cpus) {
-               err = -ENOMEM;
-               goto free_mask;
-       }
-       for (i = 0; i < nvec; i++)
-               cpus[i] = cpumask_local_spread(i, gc->numa_node);
-
        for (i = 0; i < nvec; i++) {
-               cpumask_set_cpu(cpus[i], req_mask);
                gic = &gc->irq_contexts[i];
                gic->handler = NULL;
                gic->arg = NULL;
@@ -1269,17 +1253,16 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
                irq = pci_irq_vector(pdev, i);
                if (irq < 0) {
                        err = irq;
-                       goto free_mask;
+                       goto free_irq;
                }
 
                err = request_irq(irq, mana_gd_intr, 0, gic->name, gic);
                if (err)
-                       goto free_mask;
-               irq_set_affinity_and_hint(irq, req_mask);
-               cpumask_clear(req_mask);
+                       goto free_irq;
+
+               cpu = cpumask_local_spread(i, gc->numa_node);
+               irq_set_affinity_and_hint(irq, cpumask_of(cpu));
        }
-       free_cpumask_var(req_mask);
-       kfree(cpus);
 
        err = mana_gd_alloc_res_map(nvec, &gc->msix_resource);
        if (err)
@@ -1290,13 +1273,12 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
 
        return 0;
 
-free_mask:
-       free_cpumask_var(req_mask);
-       kfree(cpus);
 free_irq:
        for (j = i - 1; j >= 0; j--) {
                irq = pci_irq_vector(pdev, j);
                gic = &gc->irq_contexts[j];
+
+               irq_update_affinity_hint(irq, NULL);
                free_irq(irq, gic);
        }
 
@@ -1324,6 +1306,9 @@ static void mana_gd_remove_irqs(struct pci_dev *pdev)
                        continue;
 
                gic = &gc->irq_contexts[i];
+
+               /* Need to clear the hint before free_irq */
+               irq_update_affinity_hint(irq, NULL);
                free_irq(irq, gic);
        }