net: mana: Fix accessing freed irq affinity_hint
authorHaiyang Zhang <haiyangz@microsoft.com>
Mon, 6 Feb 2023 21:28:49 +0000 (13:28 -0800)
committerJakub Kicinski <kuba@kernel.org>
Wed, 8 Feb 2023 05:30:22 +0000 (21:30 -0800)
commit18a048370b06a3a521219e9e5b10bdc2178ef19c
tree5ade582fe2de954de91c5df00e0ed9a13ab7723c
parentb1f4fbabbb912eb7061795461a498895bdc30f3c
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>
drivers/net/ethernet/microsoft/mana/gdma_main.c