[PATCH] pSeries hvsi char driver null pointer deref
Under certain rare circumstances, it appears that there can be be a
NULL-pointer deref when a user fiddles with terminal emeulation programs while
outpu is being sent to the console. This patch checks for and avoids a
NULL-pointer deref.
Signed-off-by: Hollis Blanchard <hollisbl@austin.ibm.com>
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c
index 41db806..54cbb58 100644
--- a/drivers/char/hvsi.c
+++ b/drivers/char/hvsi.c
@@ -311,7 +311,8 @@
/* CD went away; no more connection */
pr_debug("hvsi%i: CD dropped\n", hp->index);
hp->mctrl &= TIOCM_CD;
- if (!(hp->tty->flags & CLOCAL))
+ /* If userland hasn't done an open(2) yet, hp->tty is NULL. */
+ if (hp->tty && !(hp->tty->flags & CLOCAL))
*to_hangup = hp->tty;
}
break;