serial: sprd: Assign sprd_port after initialized to avoid wrong access
authorChunyan Zhang <chunyan.zhang@unisoc.com>
Tue, 25 Jul 2023 06:40:52 +0000 (14:40 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 13 Sep 2023 07:42:52 +0000 (09:42 +0200)
commit70f7513342f47bf3ebac8dc1a671ee0b6821c99a
tree52fc4ebc7923d8a6c256907fa47c8d26ff83e2b0
parent21608d2ba56529f883a1028e8ec612454516301b
serial: sprd: Assign sprd_port after initialized to avoid wrong access

[ Upstream commit f9608f1887568b728839d006024585ab02ef29e5 ]

The global pointer 'sprd_port' may not zero when sprd_probe returns
failure, that is a risk for sprd_port to be accessed afterward, and
may lead to unexpected errors.

For example:

There are two UART ports, UART1 is used for console and configured in
kernel command line, i.e. "console=";

The UART1 probe failed and the memory allocated to sprd_port[1] was
released, but sprd_port[1] was not set to NULL;

In UART2 probe, the same virtual address was allocated to sprd_port[2],
and UART2 probe process finally will go into sprd_console_setup() to
register UART1 as console since it is configured as preferred console
(filled to console_cmdline[]), but the console parameters (sprd_port[1])
belong to UART2.

So move the sprd_port[] assignment to where the port already initialized
can avoid the above issue.

Fixes: b7396a38fb28 ("tty/serial: Add Spreadtrum sc9836-uart driver support")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20230725064053.235448-1-chunyan.zhang@unisoc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/tty/serial/sprd_serial.c