diff mbox series

fs: Return -EFAULT if copy_to_user() fails

Message ID 1614597960-32681-1-git-send-email-wangqing@vivo.com (mailing list archive)
State New, archived
Headers show
Series fs: Return -EFAULT if copy_to_user() fails | expand

Commit Message

王擎 March 1, 2021, 11:26 a.m. UTC 
The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Signed-off-by: Wang Qing <wangqing@vivo.com>
---
 fs/select.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Matthew Wilcox March 1, 2021, 12:52 p.m. UTC | #1 
On Mon, Mar 01, 2021 at 07:26:00PM +0800, Wang Qing wrote:
> The copy_to_user() function returns the number of bytes remaining to be
> copied, but we want to return -EFAULT if the copy doesn't complete.

... which is done by the only caller.

        if (set_fd_set(n, inp, fds.res_in) ||
            set_fd_set(n, outp, fds.res_out) ||
            set_fd_set(n, exp, fds.res_ex))
                ret = -EFAULT;
diff mbox series

Patch

diff --git a/fs/select.c b/fs/select.c
index 37aaa83..93cd35b
--- a/fs/select.c
+++ b/fs/select.c
@@ -400,7 +400,7 @@  static inline unsigned long __must_check
 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
 {
 	if (ufdset)
-		return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
+		return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)) ? -EFAULT : 0;
 	return 0;
 }