[PATCH 5.10 430/599] driver core: dd: fix return value of __setup handler

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 18:09:43 EST

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

[ Upstream commit f2aad54703dbe630f9d8b235eb58e8c8cc78f37d ]

When "driver_async_probe=nulltty" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
environment strings, polluting them.

Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
driver_async_probe=nulltty", will be passed to user space.

Run /sbin/init as init process
with arguments:
with environment:

Change the return value of the __setup function to 1 to indicate
that the __setup option has been handled.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@xxxxxxxxxxxx
Fixes: 1ea61b68d0f8 ("async: Add cmdline option to specify drivers to be async probed")
Cc: Feng Tang <feng.tang@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Reported-by: Igor Zhbanov <i.zhbanov@xxxxxxxxxxxx>
Reviewed-by: Feng Tang <feng.tang@xxxxxxxxx>
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220301041829.15137-1-rdunlap@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/base/dd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 64ff137408b8..2728223c1fbc 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -771,7 +771,7 @@ static int __init save_async_options(char *buf)
pr_warn("Too long list of driver names for 'driver_async_probe'!\n");

strlcpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN);
- return 0;
+ return 1;
__setup("driver_async_probe=", save_async_options);