[PATCH] ISDN: correctly handle isdn_writebuf_stub() errors

isdn_writebuf_stub() forgets to detect memory allocation and uaccess errors.
And when that's fixed, if a error happens the caller will just keep on
looping.

So change the caller to detect the error, and to return it.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index 22759c01746a..81accdf35168 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -1177,9 +1177,8 @@ isdn_write(struct file *file, const char __user *buf, size_t count, loff_t * off
                         goto out;
                 }
                 chidx = isdn_minor2chan(minor);
-                while (isdn_writebuf_stub(drvidx, chidx, buf, count) != count)
+                while ((retval = isdn_writebuf_stub(drvidx, chidx, buf, count)) == 0)
                         interruptible_sleep_on(&dev->drv[drvidx]->snd_waitq[chidx]);
-                retval = count;
                 goto out;
         }
         if (minor <= ISDN_MINOR_CTRLMAX) {
@@ -1951,9 +1950,10 @@ isdn_writebuf_stub(int drvidx, int chan, const u_char __user * buf, int len)
         struct sk_buff *skb = alloc_skb(hl + len, GFP_ATOMIC);
 
         if (!skb)
-                return 0;
+                return -ENOMEM;
         skb_reserve(skb, hl);
-        copy_from_user(skb_put(skb, len), buf, len);
+        if (copy_from_user(skb_put(skb, len), buf, len))
+                return -EFAULT;
         ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, 1, skb);
         if (ret <= 0)
                 dev_kfree_skb(skb);