diff options
| author | Will McVicker <willmcvicker@google.com> | 2025-04-24 11:04:19 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-01 18:00:58 +0200 |
| commit | 95deee37a12364f410d22c6a8383f59738a2fef3 (patch) | |
| tree | a8e85c93096656021a2418e2eb2bc7fcbf9d26b5 /drivers/base/platform.c | |
| parent | b4432656b36e5cc1d50a1f2dc15357543add530e (diff) | |
platform: Fix race condition during DMA configure at IOMMU probe time
To avoid a race between the IOMMU probing thread and the device driver
async probing thread during configuration of the platform DMA, update
`platform_dma_configure()` to read `dev->driver` once and test if it's
NULL before using it. This ensures that we don't de-reference an invalid
platform driver pointer if the device driver is asynchronously bound
while configuring the DMA.
Fixes: bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Will McVicker <willmcvicker@google.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20250424180420.3928523-1-willmcvicker@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/platform.c')
| -rw-r--r-- | drivers/base/platform.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 1813cfd0c4bd..cfccf3ff36e7 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1440,7 +1440,7 @@ static void platform_shutdown(struct device *_dev) static int platform_dma_configure(struct device *dev) { - struct platform_driver *drv = to_platform_driver(dev->driver); + struct device_driver *drv = READ_ONCE(dev->driver); struct fwnode_handle *fwnode = dev_fwnode(dev); enum dev_dma_attr attr; int ret = 0; @@ -1451,8 +1451,8 @@ static int platform_dma_configure(struct device *dev) attr = acpi_get_dma_attr(to_acpi_device_node(fwnode)); ret = acpi_dma_configure(dev, attr); } - /* @drv may not be valid when we're called from the IOMMU layer */ - if (ret || !dev->driver || drv->driver_managed_dma) + /* @dev->driver may not be valid when we're called from the IOMMU layer */ + if (ret || !drv || to_platform_driver(drv)->driver_managed_dma) return ret; ret = iommu_device_use_default_domain(dev); |