2010-07-30 11:10:34

by Kulikov Vasiliy

[permalink] [raw]
Subject: [PATCH 9/9] sunrpc: auth_gss: misused copy_to_user() return value

copy_to_user() returns nonzero value on error, this value may be any
value between 0 and requested count, not only requested count.

Signed-off-by: Kulikov Vasiliy <[email protected]>
---
net/sunrpc/auth_gss/auth_gss.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 8da2a0e..232d7dc 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -610,7 +610,7 @@ gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
unsigned long left;

left = copy_to_user(dst, data, mlen);
- if (left == mlen) {
+ if (left)
msg->errno = -EFAULT;
return -EFAULT;
}
--
1.7.0.4



2010-07-30 17:48:04

by Myklebust, Trond

[permalink] [raw]
Subject: Re: [PATCH 9/9] sunrpc: auth_gss: misused copy_to_user() return value

On Fri, 2010-07-30 at 15:10 +0400, Kulikov Vasiliy wrote:
> copy_to_user() returns nonzero value on error, this value may be any
> value between 0 and requested count, not only requested count.
>
> Signed-off-by: Kulikov Vasiliy <[email protected]>
> ---
> net/sunrpc/auth_gss/auth_gss.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
> index 8da2a0e..232d7dc 100644
> --- a/net/sunrpc/auth_gss/auth_gss.c
> +++ b/net/sunrpc/auth_gss/auth_gss.c
> @@ -610,7 +610,7 @@ gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
> unsigned long left;
>
> left = copy_to_user(dst, data, mlen);
> - if (left == mlen) {
> + if (left)
> msg->errno = -EFAULT;
> return -EFAULT;
> }

Ditto unnecessary...

Trond