clang static analysis reports this representative issue
drivers/tty/serial/serial_core.c:2818:9: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
uart_get_info() is used the *show() functions. When uart_get_info() fails, what is reported
is garbage. So check if uart_get_info() succeeded.
Fixes: 4047b37122d1 ("serial: core: Prevent unsafe uart port access, part 1")
Signed-off-by: Tom Rix <[email protected]>
---
drivers/tty/serial/serial_core.c | 52 ++++++++++++++++++++++++--------
1 file changed, 39 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 9a85b41caa0a..4160f6711c5d 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2690,7 +2690,9 @@ static ssize_t uartclk_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.baud_base * 16);
}
@@ -2700,7 +2702,9 @@ static ssize_t type_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.type);
}
@@ -2710,7 +2714,9 @@ static ssize_t line_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.line);
}
@@ -2721,7 +2727,9 @@ static ssize_t port_show(struct device *dev,
struct tty_port *port = dev_get_drvdata(dev);
unsigned long ioaddr;
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
ioaddr = tmp.port;
if (HIGH_BITS_OFFSET)
ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
@@ -2734,7 +2742,9 @@ static ssize_t irq_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.irq);
}
@@ -2744,7 +2754,9 @@ static ssize_t flags_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "0x%X\n", tmp.flags);
}
@@ -2754,7 +2766,9 @@ static ssize_t xmit_fifo_size_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
}
@@ -2764,7 +2778,9 @@ static ssize_t close_delay_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.close_delay);
}
@@ -2774,7 +2790,9 @@ static ssize_t closing_wait_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.closing_wait);
}
@@ -2784,7 +2802,9 @@ static ssize_t custom_divisor_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.custom_divisor);
}
@@ -2794,7 +2814,9 @@ static ssize_t io_type_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.io_type);
}
@@ -2804,7 +2826,9 @@ static ssize_t iomem_base_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
}
@@ -2814,7 +2838,9 @@ static ssize_t iomem_reg_shift_show(struct device *dev,
struct serial_struct tmp;
struct tty_port *port = dev_get_drvdata(dev);
- uart_get_info(port, &tmp);
+ if (uart_get_info(port, &tmp))
+ return 0;
+
return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
}
--
2.27.0
On Sun, May 29, 2022 at 6:46 AM Tom Rix <[email protected]> wrote:
>
> clang static analysis reports this representative issue
> drivers/tty/serial/serial_core.c:2818:9: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
> return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> uart_get_info() is used the *show() functions. When uart_get_info() fails, what is reported
> is garbage. So check if uart_get_info() succeeded.
Hi Tom,
Thanks for the patch. What do you think about throwing __must_check on
the definition of uart_get_info with a comment that members of the
retinfo param will not be initialized if the return value is not zero?
Otherwise, patch LGTM.
Reviewed-by: Nick Desaulniers <[email protected]>
>
> Fixes: 4047b37122d1 ("serial: core: Prevent unsafe uart port access, part 1")
> Signed-off-by: Tom Rix <[email protected]>
> ---
> drivers/tty/serial/serial_core.c | 52 ++++++++++++++++++++++++--------
> 1 file changed, 39 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 9a85b41caa0a..4160f6711c5d 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2690,7 +2690,9 @@ static ssize_t uartclk_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.baud_base * 16);
> }
>
> @@ -2700,7 +2702,9 @@ static ssize_t type_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.type);
> }
>
> @@ -2710,7 +2714,9 @@ static ssize_t line_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.line);
> }
>
> @@ -2721,7 +2727,9 @@ static ssize_t port_show(struct device *dev,
> struct tty_port *port = dev_get_drvdata(dev);
> unsigned long ioaddr;
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> ioaddr = tmp.port;
> if (HIGH_BITS_OFFSET)
> ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
> @@ -2734,7 +2742,9 @@ static ssize_t irq_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.irq);
> }
>
> @@ -2744,7 +2754,9 @@ static ssize_t flags_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "0x%X\n", tmp.flags);
> }
>
> @@ -2754,7 +2766,9 @@ static ssize_t xmit_fifo_size_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.xmit_fifo_size);
> }
>
> @@ -2764,7 +2778,9 @@ static ssize_t close_delay_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.close_delay);
> }
>
> @@ -2774,7 +2790,9 @@ static ssize_t closing_wait_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.closing_wait);
> }
>
> @@ -2784,7 +2802,9 @@ static ssize_t custom_divisor_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.custom_divisor);
> }
>
> @@ -2794,7 +2814,9 @@ static ssize_t io_type_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.io_type);
> }
>
> @@ -2804,7 +2826,9 @@ static ssize_t iomem_base_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base);
> }
>
> @@ -2814,7 +2838,9 @@ static ssize_t iomem_reg_shift_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
> +
> return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
> }
>
> --
> 2.27.0
>
--
Thanks,
~Nick Desaulniers
On Sun, May 29, 2022 at 4:09 PM Tom Rix <[email protected]> wrote:
>
> clang static analysis reports this representative issue
> drivers/tty/serial/serial_core.c:2818:9: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
> return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> uart_get_info() is used the *show() functions. When uart_get_info() fails, what is reported
in the ?
> is garbage. So check if uart_get_info() succeeded.
...
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
I don't think this is correct. If something fails we need to inform the caller.
I think more about
int ret;
ret = uart_get_info(...);
if (ret)
return ret;
But I haven't looked at the uart_get_info() implementation, so the
above might be wrong.
> return sprintf(buf, "%d\n", tmp.baud_base * 16);
Ditto for the rest.
--
With Best Regards,
Andy Shevchenko
On Sun, May 29, 2022 at 09:46:05AM -0400, Tom Rix wrote:
> clang static analysis reports this representative issue
> drivers/tty/serial/serial_core.c:2818:9: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
> return sprintf(buf, "%d\n", tmp.iomem_reg_shift);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> uart_get_info() is used the *show() functions. When uart_get_info() fails, what is reported
> is garbage. So check if uart_get_info() succeeded.
>
> Fixes: 4047b37122d1 ("serial: core: Prevent unsafe uart port access, part 1")
> Signed-off-by: Tom Rix <[email protected]>
> ---
> drivers/tty/serial/serial_core.c | 52 ++++++++++++++++++++++++--------
> 1 file changed, 39 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 9a85b41caa0a..4160f6711c5d 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2690,7 +2690,9 @@ static ssize_t uartclk_show(struct device *dev,
> struct serial_struct tmp;
> struct tty_port *port = dev_get_drvdata(dev);
>
> - uart_get_info(port, &tmp);
> + if (uart_get_info(port, &tmp))
> + return 0;
As Andy pointed out, this is an error, don't tell userspace that all
went well and yet you returned no data? That will just confuse it.
thanks,
greg k-h