[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>

diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index 22759c01746af5d71a1c016d79716d4ec3406c91..81accdf35168c4607358de042a379684d715f2d0 100644 (file)
--- 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);