diff options
Diffstat (limited to 'drivers/usb')
-rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 12dbdaf..63314ed 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -647,15 +647,26 @@ static void ffs_user_copy_worker(struct work_struct *work) if (io_data->read && ret > 0) { int i; size_t pos = 0; + + /* + * Since req->length may be bigger than io_data->len (after + * being rounded up to maxpacketsize), we may end up with more + * data then user space has space for. + */ + ret = min_t(int, ret, io_data->len); + use_mm(io_data->mm); for (i = 0; i < io_data->nr_segs; i++) { + size_t len = min_t(size_t, ret - pos, + io_data->iovec[i].iov_len); + if (!len) + break; if (unlikely(copy_to_user(io_data->iovec[i].iov_base, - &io_data->buf[pos], - io_data->iovec[i].iov_len))) { + &io_data->buf[pos], len))) { ret = -EFAULT; break; } - pos += io_data->iovec[i].iov_len; + pos += len; } unuse_mm(io_data->mm); } @@ -687,7 +698,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) struct ffs_epfile *epfile = file->private_data; struct ffs_ep *ep; char *data = NULL; - ssize_t ret, data_len; + ssize_t ret, data_len = -EINVAL; int halt; /* Are we still active? */ @@ -787,13 +798,30 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) /* Fire the request */ struct usb_request *req; + /* + * Sanity Check: even though data_len can't be used + * uninitialized at the time I write this comment, some + * compilers complain about this situation. + * In order to keep the code clean from warnings, data_len is + * being initialized to -EINVAL during its declaration, which + * means we can't rely on compiler anymore to warn no future + * changes won't result in data_len being used uninitialized. + * For such reason, we're adding this redundant sanity check + * here. + */ + if (unlikely(data_len == -EINVAL)) { + WARN(1, "%s: data_len == -EINVAL\n", __func__); + ret = -EINVAL; + goto error_lock; + } + if (io_data->aio) { req = usb_ep_alloc_request(ep->ep, GFP_KERNEL); if (unlikely(!req)) goto error_lock; req->buf = data; - req->length = io_data->len; + req->length = data_len; io_data->buf = data; io_data->ep = ep->ep; @@ -815,7 +843,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) req = ep->req; req->buf = data; - req->length = io_data->len; + req->length = data_len; req->context = &done; req->complete = ffs_epfile_io_complete; |