kmsg: /dev/kmsg - properly return possible copy_from_user() failure

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 50c96b5651b6..852269adad25 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -389,8 +389,10 @@ static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
 
         line = buf;
         for (i = 0; i < count; i++) {
-                if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len))
+                if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+                        ret = -EFAULT;
                         goto out;
+                }
                 line += iv[i].iov_len;
         }