[patch v2] fcntl: return -EFAULT if copy_to_user fails

From: Dan Carpenter
Date: Thu Jun 03 2010 - 06:36:14 EST


copy_to_user() returns the number of bytes remaining, but we want to
return -EFAULT.
ret = fcntl(fd, F_SETOWN_EX, NULL);
With the original code ret would be 8 here.

V2: Takuya Yoshikawa pointed out a similar issue in f_getown_ex()

Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>

diff --git a/fs/fcntl.c b/fs/fcntl.c
index f74d270..51e11bf 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -274,7 +274,7 @@ static int f_setown_ex(struct file *filp, unsigned long arg)

ret = copy_from_user(&owner, owner_p, sizeof(owner));
if (ret)
- return ret;
+ return -EFAULT;

switch (owner.type) {
case F_OWNER_TID:
@@ -332,8 +332,11 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
}
read_unlock(&filp->f_owner.lock);

- if (!ret)
+ if (!ret) {
ret = copy_to_user(owner_p, &owner, sizeof(owner));
+ if (ret)
+ ret = -EFAULT;
+ }
return ret;
}

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