[PATCH 2/3] vhost-net: fix to check the return value of copy_to/from_user() correctly
From: Takuya Yoshikawa <hidden>
Date: 2010-05-27 10:01:35
Also in:
kvm, virtualization
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
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 <redacted> --- 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