This is a note to let you know that I've just added the patch titled
driver: core: Fix list corruption after device_del()
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-testing 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 be merged to the driver-core-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 66482f640755b31cb94371ff6cef17400cda6db5 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Tue, 8 Dec 2020 20:03:26 +0100
Subject: driver: core: Fix list corruption after device_del()
The device_links_purge() function (called from device_del()) tries to
remove the links.needs_suppliers list entry, but it's using
list_del(), hence it doesn't initialize after the removal. This is OK
for normal cases where device_del() is called via device_destroy().
However, it's not guaranteed that the device object will be really
deleted soon after device_del(). In a minor case like HD-audio codec
reconfiguration that re-initializes the device after device_del(), it
may lead to a crash by the corrupted list entry.
As a simple fix, replace list_del() with list_del_init() in order to
make the list intact after the device_del() call.
Fixes: e2ae9bcc4aaa ("driver core: Add support for linking devices during device addition")
Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Link: https://lore.kernel.org/r/20201208190326.27531-1-tiwai@xxxxxxx
Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 1165a80f8010..ba5a3cac6571 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1384,7 +1384,7 @@ static void device_links_purge(struct device *dev)
return;
mutex_lock(&wfs_lock);
- list_del(&dev->links.needs_suppliers);
+ list_del_init(&dev->links.needs_suppliers);
mutex_unlock(&wfs_lock);
/*
--
2.29.2
