copy_to/from_user() returns the number of bytes that could not be copied. So we need to check if it is not zero, and in that case, we should return the error number -EFAULT rather than directly return the return value from copy_to/from_user().
Signed-off-by: Takuya Yoshikawa <[email protected]> --- drivers/vhost/net.c | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index aa88911..0f41c91 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -593,17 +593,17 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, int r; switch (ioctl) { case VHOST_NET_SET_BACKEND: - r = copy_from_user(&backend, argp, sizeof backend); - if (r < 0) - return r; + if (copy_from_user(&backend, argp, sizeof backend)) + return -EFAULT; return vhost_net_set_backend(n, backend.index, backend.fd); case VHOST_GET_FEATURES: features = VHOST_FEATURES; - return copy_to_user(featurep, &features, sizeof features); + if (copy_to_user(featurep, &features, sizeof features)) + return -EFAULT; + return 0; case VHOST_SET_FEATURES: - r = copy_from_user(&features, featurep, sizeof features); - if (r < 0) - return r; + if (copy_from_user(&features, featurep, sizeof features)) + return -EFAULT; if (features & ~VHOST_FEATURES) return -EOPNOTSUPP; return vhost_net_set_features(n, features); -- 1.7.0.4 _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
