[PATCH] usb: ftdi-elan: Fix undefined behaviour

From: cgel . zte
Date: Fri Apr 01 2022 - 03:58:01 EST


From: Lv Ruyi <lv.ruyi@xxxxxxxxxx>

The use of zero-sized array causes undefined behaviour when it is not
the last member in a structure. As it happens to be in this case.

Also, the current code makes use of a language extension to the C90
standard, but the preferred mechanism to declare variable-length
types such as this one is a flexible array member, introduced in
C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last. Which is beneficial
to cultivate a high-quality code.

Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
Signed-off-by: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
---
drivers/usb/misc/ftdi-elan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/misc/ftdi-elan.c b/drivers/usb/misc/ftdi-elan.c
index 6c38c62d29b2..e818d2ed6831 100644
--- a/drivers/usb/misc/ftdi-elan.c
+++ b/drivers/usb/misc/ftdi-elan.c
@@ -171,7 +171,6 @@ struct usb_ftdi {
struct delayed_work command_work;
struct delayed_work respond_work;
struct u132_platform_data platform_data;
- struct resource resources[0];
struct platform_device platform_dev;
unsigned char *bulk_in_buffer;
size_t bulk_in_size;
@@ -185,6 +184,7 @@ struct usb_ftdi {
int expected;
int received;
int ed_found;
+ struct resource resources[];
};
#define kref_to_usb_ftdi(d) container_of(d, struct usb_ftdi, kref)
#define platform_device_to_usb_ftdi(d) container_of(d, struct usb_ftdi, \
--
2.25.1