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nvme-pci: fix race condition between reset and nvme_dev_disable()

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nvme_dev_disable() modifies the dev->online_queues field, therefore
nvme_pci_update_nr_queues() should avoid racing against it, otherwise
we could end up passing invalid values to blk_mq_update_nr_hw_queues().

 WARNING: CPU: 39 PID: 61303 at drivers/pci/msi/api.c:347
          pci_irq_get_affinity+0x187/0x210
 Workqueue: nvme-reset-wq nvme_reset_work [nvme]
 RIP: 0010:pci_irq_get_affinity+0x187/0x210
 Call Trace:
  <TASK>
  ? blk_mq_pci_map_queues+0x87/0x3c0
  ? pci_irq_get_affinity+0x187/0x210
  blk_mq_pci_map_queues+0x87/0x3c0
  nvme_pci_map_queues+0x189/0x460 [nvme]
  blk_mq_update_nr_hw_queues+0x2a/0x40
  nvme_reset_work+0x1be/0x2a0 [nvme]

Fix the bug by locking the shutdown_lock mutex before using
dev->online_queues. Give up if nvme_dev_disable() is running or if
it has been executed already.

Fixes: 949928c1c7 ("NVMe: Fix possible queue use after freed")
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This commit is contained in:
Maurizio Lombardi 2024-10-15 13:21:00 +02:00 committed by Keith Busch
parent 1f021341ee
commit 26bc0a81f6
1 changed files with 16 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/nvme/host/pci.c
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@ -2506,17 +2506,29 @@ static unsigned int nvme_pci_nr_maps(struct nvme_dev *dev)
return 1;
}
static void nvme_pci_update_nr_queues(struct nvme_dev *dev)
static bool nvme_pci_update_nr_queues(struct nvme_dev *dev)
{
if (!dev->ctrl.tagset) {
nvme_alloc_io_tag_set(&dev->ctrl, &dev->tagset, &nvme_mq_ops,
nvme_pci_nr_maps(dev), sizeof(struct nvme_iod));
return;
return true;
}
/* Give up if we are racing with nvme_dev_disable() */
if (!mutex_trylock(&dev->shutdown_lock))
return false;
/* Check if nvme_dev_disable() has been executed already */
if (!dev->online_queues) {
mutex_unlock(&dev->shutdown_lock);
return false;
}
blk_mq_update_nr_hw_queues(&dev->tagset, dev->online_queues - 1);
/* free previously allocated queues that are no longer usable */
nvme_free_queues(dev, dev->online_queues);
mutex_unlock(&dev->shutdown_lock);
return true;
}
static int nvme_pci_enable(struct nvme_dev *dev)
@ -2797,7 +2809,8 @@ static void nvme_reset_work(struct work_struct *work)
nvme_dbbuf_set(dev);
nvme_unquiesce_io_queues(&dev->ctrl);
nvme_wait_freeze(&dev->ctrl);
nvme_pci_update_nr_queues(dev);
if (!nvme_pci_update_nr_queues(dev))
goto out;
nvme_unfreeze(&dev->ctrl);
} else {
dev_warn(dev->ctrl.device, "IO queues lost\n");