This is a note to let you know that I've just added the patch titled
drivers core: Fix oops when driver probe fails
to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 4d1014c1816c0395eca5d1d480f196a4c63119d0 Mon Sep 17 00:00:00 2001
From: Filip Schauer filip@mg6.at Date: Tue, 27 Jul 2021 13:23:11 +0200 Subject: drivers core: Fix oops when driver probe fails
dma_range_map is freed to early, which might cause an oops when a driver probe fails. Call trace: is_free_buddy_page+0xe4/0x1d4 __free_pages+0x2c/0x88 dma_free_contiguous+0x64/0x80 dma_direct_free+0x38/0xb4 dma_free_attrs+0x88/0xa0 dmam_release+0x28/0x34 release_nodes+0x78/0x8c devres_release_all+0xa8/0x110 really_probe+0x118/0x2d0 __driver_probe_device+0xc8/0xe0 driver_probe_device+0x54/0xec __driver_attach+0xe0/0xf0 bus_for_each_dev+0x7c/0xc8 driver_attach+0x30/0x3c bus_add_driver+0x17c/0x1c4 driver_register+0xc0/0xf8 __platform_driver_register+0x34/0x40 ...
This issue is introduced by commit d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed"). It frees dma_range_map before the call to devres_release_all, which is too early. The solution is to free dma_range_map only after devres_release_all.
Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed") Cc: stable stable@vger.kernel.org Signed-off-by: Filip Schauer filip@mg6.at Link: https://lore.kernel.org/r/20210727112311.GA7645@DESKTOP-E8BN1B0.localdomain Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/base/dd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index daeb9b5763ae..437cd61343b2 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -653,8 +653,6 @@ static int really_probe(struct device *dev, struct device_driver *drv) else if (drv->remove) drv->remove(dev); probe_failed: - kfree(dev->dma_range_map); - dev->dma_range_map = NULL; if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev); @@ -662,6 +660,8 @@ static int really_probe(struct device *dev, struct device_driver *drv) device_links_no_driver(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);