| Message ID | 20220404143842.16960-1-linmq006@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | serial: 8250_aspeed_vuart: Fix potential NULL dereference in aspeed_vuart_probe | expand |
On Mon, Apr 04, 2022 at 02:38:40PM +0000, Miaoqian Lin wrote: > platform_get_resource() may fail and return NULL, so we should > better check it's return value to avoid a NULL pointer dereference. > > Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") > Signed-off-by: Miaoqian Lin <linmq006@gmail.com> > --- > drivers/tty/serial/8250/8250_aspeed_vuart.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c > index 93fe10c680fb..9d2a7856784f 100644 > --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c > +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c > @@ -429,6 +429,8 @@ static int aspeed_vuart_probe(struct platform_device *pdev) > timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0); > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -EINVAL; How did you test this change was correct?
On Mon, Apr 04, 2022 at 04:45:50PM +0200, Greg Kroah-Hartman wrote: > On Mon, Apr 04, 2022 at 02:38:40PM +0000, Miaoqian Lin wrote: > > platform_get_resource() may fail and return NULL, so we should > > better check it's return value to avoid a NULL pointer dereference. > > > > Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") > > Signed-off-by: Miaoqian Lin <linmq006@gmail.com> > > --- > > drivers/tty/serial/8250/8250_aspeed_vuart.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c > > index 93fe10c680fb..9d2a7856784f 100644 > > --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c > > +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c > > @@ -429,6 +429,8 @@ static int aspeed_vuart_probe(struct platform_device *pdev) > > timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0); > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + if (!res) > > + return -EINVAL; > > How did you test this change was correct? Hi, I look into the implementation of platform_get_resource(), and do cross-check the usages of it in the codebase, especially the usages in other probe function. And I go through some simliar bugfix commits in the revision history—— add check for return value of platform_get_resource() in probe functions，to learn the way to fix this kind of bugs. But sorry I don't have the corresponding device for running test.
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c index 93fe10c680fb..9d2a7856784f 100644 --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -429,6 +429,8 @@ static int aspeed_vuart_probe(struct platform_device *pdev) timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; memset(&port, 0, sizeof(port)); port.port.private_data = vuart;
platform_get_resource() may fail and return NULL, so we should better check it's return value to avoid a NULL pointer dereference. Fixes: 54da3e381c2b ("serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> --- drivers/tty/serial/8250/8250_aspeed_vuart.c | 2 ++ 1 file changed, 2 insertions(+)