drivers/isdn/i4l/isdn_common.c fix small resource leak

commit 4fc89e3911aa5357b55b85b60c4beaeb8a48a290 upstream

Coverity CID: 1356 RESOURCE_LEAK

I found a very old patch for this that was Acked but did not get applied
https://lists.linux-foundation.org/pipermail/kernel-janitors/2006-September/016362.html

There looks to be a small leak in isdn_writebuf_stub() in isdn_common.c, when
copy_from_user() returns an un-copied data length (length != 0).  The below
patch should be a minimally invasive fix.

Signed-off-by: Darren Jenkins <darrenrjenkins@gmail.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index d4ad6992f776c895d637b72c779b04fd5dd7915e..37fcb3845412876656165a5649f50e1cab5d0d0a 100644 (file)
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -1977,8 +1977,10 @@ isdn_writebuf_stub(int drvidx, int chan, const u_char __user * buf, int len)
        if (!skb)
                return -ENOMEM;
        skb_reserve(skb, hl);
-       if (copy_from_user(skb_put(skb, len), buf, len))
+       if (copy_from_user(skb_put(skb, len), buf, len)) {
+               dev_kfree_skb(skb);
                return -EFAULT;
+       }
        ret = dev->drv[drvidx]->interface->writebuf_skb(drvidx, chan, 1, skb);
        if (ret <= 0)
                dev_kfree_skb(skb);