From: Christophe JAILLET christophe.jaillet@wanadoo.fr
[ Upstream commit a4a97ab3db5c081eb6e7dba91306adefb461e0bd ]
If xdbc_bulk_write() fails, the values in 'buf' can be anything. So the string is not guaranteed to be NULL terminated when xdbc_trace() is called.
Reserve an extra byte, which will be zeroed automatically because 'buf' is a static variable, in order to avoid troubles, should it happen.
Fixes: aeb9dd1de98c ("usb/early: Add driver for xhci debug capability") Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr Link: https://lore.kernel.org/r/d6a7562c5e839a195cee85db6dc81817f9372cb1.167501618... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/early/xhci-dbc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index bfb7e2b852996..7ef0a4b397620 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -874,7 +874,8 @@ static int xdbc_bulk_write(const char *bytes, int size)
static void early_xdbc_write(struct console *con, const char *str, u32 n) { - static char buf[XDBC_MAX_PACKET]; + /* static variables are zeroed, so buf is always NULL terminated */ + static char buf[XDBC_MAX_PACKET + 1]; int chunk, ret; int use_cr = 0;