Avoid kernel-usb-infoleak by initializing all memory written to device. The buffer length uses 32bit alignment which might cause some buffer data to be read without any initialization. Reported-by: syzbot+8f282cce71948071c335@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://lore.kernel.org/all/0000000000006f6622061eb52dba@xxxxxxxxxx/T/ Signed-off-by: Pimyn Girgis <bemenboshra2001@xxxxxxxxx> (Google) --- drivers/usb/class/usbtmc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index ffc9c6fdd7e1..d79a08dfb54d 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -21,6 +21,7 @@ #include <linux/usb.h> #include <linux/compat.h> #include <linux/usb/tmc.h> +#include <linux/string.h> /* Increment API VERSION when changing tmc.h with new flags or ioctls * or when changing a significant behavior of the driver. @@ -1169,6 +1170,8 @@ static ssize_t usbtmc_generic_write(struct usbtmc_file_data *file_data, * (size + 3 & ~3) rounds up and simplifies user code */ aligned = (this_part + 3) & ~3; + /* Initialize the remaining part of the buffer */ + memzero_explicit(buffer + this_part, aligned - this_part); dev_dbg(dev, "write(size:%u align:%u done:%u)\n", (unsigned int)this_part, (unsigned int)aligned, -- 2.47.0.rc0.187.ge670bccf7e-goog
