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authorMårten Lindahl <marten.lindahl@axis.com>2022-02-16 12:41:28 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-03-02 13:42:56 +0300
commit8fe4da55246ac3cff5947485f466e5537c5bc294 (patch)
treef004c23e12c25867eb5e57f996e23a9764f5c0c8 /drivers/base
parent214824764308ae9b3dc0a99e369ef9a68af05923 (diff)
downloadlinux-8fe4da55246ac3cff5947485f466e5537c5bc294.tar.xz
driver core: Free DMA range map when device is released
commit d8f7a5484f2188e9af2d9e4e587587d724501b12 upstream. When unbinding/binding a driver with DMA mapped memory, the DMA map is not freed before the driver is reloaded. This leads to a memory leak when the DMA map is overwritten when reprobing the driver. This can be reproduced with a platform driver having a dma-range: dummy { ... #address-cells = <0x2>; #size-cells = <0x2>; ranges; dma-ranges = <...>; ... }; and then unbinding/binding it: ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/unbind DMA map object 0xffffff800b0ae540 still being held by &pdev->dev ~# echo soc:dummy >/sys/bus/platform/drivers/<driver>/bind ~# echo scan > /sys/kernel/debug/kmemleak ~# cat /sys/kernel/debug/kmemleak unreferenced object 0xffffff800b0ae540 (size 64): comm "sh", pid 833, jiffies 4295174550 (age 2535.352s) hex dump (first 32 bytes): 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 80 00 00 00 00 00 00 00 80 00 00 00 00 ................ backtrace: [<ffffffefd1694708>] create_object.isra.0+0x108/0x344 [<ffffffefd1d1a850>] kmemleak_alloc+0x8c/0xd0 [<ffffffefd167e2d0>] __kmalloc+0x440/0x6f0 [<ffffffefd1a960a4>] of_dma_get_range+0x124/0x220 [<ffffffefd1a8ce90>] of_dma_configure_id+0x40/0x2d0 [<ffffffefd198b68c>] platform_dma_configure+0x5c/0xa4 [<ffffffefd198846c>] really_probe+0x8c/0x514 [<ffffffefd1988990>] __driver_probe_device+0x9c/0x19c [<ffffffefd1988cd8>] device_driver_attach+0x54/0xbc [<ffffffefd1986634>] bind_store+0xc4/0x120 [<ffffffefd19856e0>] drv_attr_store+0x30/0x44 [<ffffffefd173c9b0>] sysfs_kf_write+0x50/0x60 [<ffffffefd173c1c4>] kernfs_fop_write_iter+0x124/0x1b4 [<ffffffefd16a013c>] new_sync_write+0xdc/0x160 [<ffffffefd16a256c>] vfs_write+0x23c/0x2a0 [<ffffffefd16a2758>] ksys_write+0x64/0xec To prevent this we should free the dma_range_map when the device is released. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset") Cc: stable <stable@vger.kernel.org> Suggested-by: Rob Herring <robh@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> Link: https://lore.kernel.org/r/20220216094128.4025861-1-marten.lindahl@axis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/dd.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 81ad4f867f02..64ff137408b8 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -592,6 +592,9 @@ re_probe:
drv->remove(dev);
devres_release_all(dev);
+ arch_teardown_dma_ops(dev);
+ kfree(dev->dma_range_map);
+ dev->dma_range_map = NULL;
driver_sysfs_remove(dev);
dev->driver = NULL;
dev_set_drvdata(dev, NULL);
@@ -1168,6 +1171,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
devres_release_all(dev);
arch_teardown_dma_ops(dev);
+ kfree(dev->dma_range_map);
+ dev->dma_range_map = NULL;
dev->driver = NULL;
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)