usb: f_fs: off by one bug in _ffs_func_bind()

commit 0015f9156092d07b3ec06d37d014328419d5832e upstream.

This loop is supposed to set all the .num[] values to -1 but it's off by
one so it skips the first element and sets one element past the end of
the array.

I've cleaned up the loop a little as well.

Fixes: ddf8abd25994 ('USB: f_fs: the FunctionFS driver')
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 97ef75af9632d81c093b85160363cee2fb5a6525..803c503a2e3d262b8a6ee858fab929596c84de43 100644 (file)
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -2740,6 +2740,7 @@ static int _ffs_func_bind(struct usb_configuration *c,
                func->ffs->ss_descs_count;
 
        int fs_len, hs_len, ss_len, ret, i;
+       struct ffs_ep *eps_ptr;
 
        /* Make it a single chunk, less management later on */
        vla_group(d);
@@ -2788,12 +2789,9 @@ static int _ffs_func_bind(struct usb_configuration *c,
               ffs->raw_descs_length);
 
        memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
-       for (ret = ffs->eps_count; ret; --ret) {
-               struct ffs_ep *ptr;
-
-               ptr = vla_ptr(vlabuf, d, eps);
-               ptr[ret].num = -1;
-       }
+       eps_ptr = vla_ptr(vlabuf, d, eps);
+       for (i = 0; i < ffs->eps_count; i++)
+               eps_ptr[i].num = -1;
 
        /* Save pointers
         * d_eps == vlabuf, func->eps used to kfree vlabuf later