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| author | Stepan Ionichev <sozdayvek@gmail.com> | 2026-05-08 23:12:37 +0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-05-22 11:45:34 +0200 |
| commit | 941c9f84c9b6310f7aaa1c8c785dcc634ee33050 (patch) | |
| tree | 953e4c2ed51eb658e25517e38f1efcc8aa385c6c /drivers/tty | |
| parent | ab5eadfea17e9aae0760eec8f730a71a4be9ba5e (diff) | |
| download | linux-next-941c9f84c9b6310f7aaa1c8c785dcc634ee33050.tar.gz linux-next-941c9f84c9b6310f7aaa1c8c785dcc634ee33050.zip | |
tty: serial: 8250: protect against NULL uart->port.dev in register
serial8250_register_8250_port() conditionally copies uart->port.dev
from up->port.dev only when up->port.dev is non-NULL:
if (up->port.dev) {
uart->port.dev = up->port.dev;
...
}
So if both the existing uart slot and up have a NULL ->dev,
uart->port.dev remains NULL. The very next ACPI companion check
then dereferences it unconditionally:
if (!has_acpi_companion(uart->port.dev)) {
has_acpi_companion() reads dev->fwnode without a NULL guard
(include/linux/acpi.h), so this NULL-derefs the kernel for the
remaining no-dev case rather than just skipping the
mctrl_gpio_init() initialisation as intended.
smatch flags the inconsistency:
drivers/tty/serial/8250/8250_core.c:767
serial8250_register_8250_port() error: 'uart->port.dev' could be
null (see line 719)
Guard the call with a NULL check so register continues to work
for callers that legitimately have no parent device (legacy
non-OF/non-ACPI registrations).
No functional change for callers that pass a non-NULL ->dev.
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Link: https://patch.msgid.link/20260508181237.11146-1-sozdayvek@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index a428e88938eb..e136cec0c0be 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -764,7 +764,7 @@ int serial8250_register_8250_port(const struct uart_8250_port *up) * Only call mctrl_gpio_init(), if the device has no ACPI * companion device */ - if (!has_acpi_companion(uart->port.dev)) { + if (uart->port.dev && !has_acpi_companion(uart->port.dev)) { struct mctrl_gpios *gpios = mctrl_gpio_init(&uart->port, 0); if (IS_ERR(gpios)) { ret = PTR_ERR(gpios); |