From: Changming Liu charley.ashbringer@gmail.com
[ Upstream commit 2b53a19284f537168fb506f2f40d7fda40a01162 ]
The char buffer buf, receives data directly from user space, so its content might be negative and its elements are left shifted to form an unsigned integer.
Since left shifting a negative value is undefined behavior, thus change the char to u8 to elimintate this UB.
Signed-off-by: Changming Liu charley.ashbringer@gmail.com Link: https://lore.kernel.org/r/20200711043018.928-1-charley.ashbringer@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/misc/sisusbvga/sisusb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/misc/sisusbvga/sisusb.c b/drivers/usb/misc/sisusbvga/sisusb.c index 6376be1f5fd2..4877bf82ad39 100644 --- a/drivers/usb/misc/sisusbvga/sisusb.c +++ b/drivers/usb/misc/sisusbvga/sisusb.c @@ -761,7 +761,7 @@ static int sisusb_write_mem_bulk(struct sisusb_usb_data *sisusb, u32 addr, u8 swap8, fromkern = kernbuffer ? 1 : 0; u16 swap16; u32 swap32, flag = (length >> 28) & 1; - char buf[4]; + u8 buf[4];
/* if neither kernbuffer not userbuffer are given, assume * data in obuf