6.6-stable review patch. If anyone has any objections, please let me know.
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From: Maurizio Lombardi mlombard@redhat.com
[ Upstream commit 26bc0a81f64ce00fc4342c38eeb2eddaad084dd2 ]
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: 949928c1c731 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/pci.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 61c9b175e035f..b701969cf1c2a 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2469,17 +2469,29 @@ 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) @@ -2760,7 +2772,8 @@ 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");