[PATCH net] vhost_vdpa: Return -EFUALT if copy_from_user() fails
From: Dan Carpenter <hidden>
Date: 2020-10-23 12:09:09
Also in:
kernel-janitors, kvm, virtualization
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
The copy_to/from_user() functions return the number of bytes which we
weren't able to copy but the ioctl should return -EFAULT if they fail.
Fixes: a127c5bbb6a8 ("vhost-vdpa: fix backend feature ioctls")
Signed-off-by: Dan Carpenter <redacted>
---
drivers/vhost/vdpa.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 62a9bb0efc55..c94a97b6bd6d 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c@@ -428,12 +428,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, void __user *argp = (void __user *)arg; u64 __user *featurep = argp; u64 features; - long r; + long r = 0; if (cmd == VHOST_SET_BACKEND_FEATURES) { - r = copy_from_user(&features, featurep, sizeof(features)); - if (r) - return r; + if (copy_from_user(&features, featurep, sizeof(features))) + return -EFAULT; if (features & ~VHOST_VDPA_BACKEND_FEATURES) return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features);
@@ -476,7 +475,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, break; case VHOST_GET_BACKEND_FEATURES: features = VHOST_VDPA_BACKEND_FEATURES; - r = copy_to_user(featurep, &features, sizeof(features)); + if (copy_to_user(featurep, &features, sizeof(features))) + r = -EFAULT; break; default: r = vhost_dev_ioctl(&v->vdev, cmd, argp);