| Message ID | d6a7562c5e839a195cee85db6dc81817f9372cb1.1675016180.git.christophe.jaillet@wanadoo.fr |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] usb: early: xhci-dbc: Fix a potential out-of-bound memory access | expand |
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index 797047154820..f3e23be227d4 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;
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> --- drivers/usb/early/xhci-dbc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)