| Message ID | 155727337603.292046.13101332703665246702.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | e615a191216e3fb4e9c0d239007f2b0cd48f28bf |
| Headers | show |
| Series | mm/devm_memremap_pages: Fix page release race | expand |
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index c52298d76e64..595a534bd749 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -208,13 +208,15 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, pci_bus_address(pdev, bar) + offset, resource_size(&pgmap->res), dev_to_node(&pdev->dev)); if (error) - goto pgmap_free; + goto pages_free; pci_info(pdev, "added peer-to-peer DMA memory %pR\n", &pgmap->res); return 0; +pages_free: + devm_memunmap_pages(&pdev->dev, pgmap); pgmap_free: devm_kfree(&pdev->dev, pgmap); return error;
The pci_p2pdma_add_resource() implementation immediately frees the pgmap if gen_pool_add_virt() fails. However, that means that when @dev triggers a devres release devm_memremap_pages_release() will crash trying to access the freed @pgmap. Use the new devm_memunmap_pages() to manually free the mapping in the error path. Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/pci/p2pdma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)