From: Jiri Slaby <jirislaby@gmail.com>
Date: Tue, 23 Oct 2007 03:45:13 +0000 (-0700)
Subject: Char: cyclades, fix potential NULL dereference
X-Git-Tag: v2.6.24-rc1~50
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7fa57a0cd98bdd163eeb5f15cbe234c3a0cf68a1;p=linux-2.6

Char: cyclades, fix potential NULL dereference

ztxdone is jumped to even if tty is NULL and tty_wakeup placed after
this label doesn't expect NULLed parameter, so this will cause an oops
in some situations (why they scheduled a wakeup there before remove
bottom half processing patch?).

wakeup only in the case when we have non-null tty struct.

Spotted by Adrian Bunk.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index d1bd0f08a3..e4f579c3e2 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -1602,8 +1602,8 @@ static void cyz_handle_tx(struct cyclades_port *info,
 			info->icount.tx++;
 		}
 #endif
-ztxdone:
 		tty_wakeup(tty);
+ztxdone:
 		/* Update tx_put */
 		cy_writel(&buf_ctrl->tx_put, tx_put);
 	}