From 229395c90aadbadef76bacf52b9cb3326f509e93 Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Sat, 5 Aug 2006 12:14:36 -0700 Subject: [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 Signed-off-by: Linas Vepstas Cc: Paul Fulghum Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/hvsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/char/hvsi.c') diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c index 41db8060e8f7..54cbb58b8740 100644 --- a/drivers/char/hvsi.c +++ b/drivers/char/hvsi.c @@ -311,7 +311,8 @@ static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet, /* 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; -- cgit v1.2.3 From 64e0cc38b69b8d43ab9793f50e4bb09cea0e6bb9 Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Sat, 5 Aug 2006 12:14:39 -0700 Subject: [PATCH] pSeries: hvsi char driver janitorial cleanup A set of tty line discipline cleanup patches were introduced before the dawn of time, in kernel version 2.4.21. This patch performs that cleanup for the hvsi driver. The hvsi driver is used only on IBM pSeries PowerPC boxes. The driver was originally written by Hollis Blanchard, who has delegated maintainership to me. So this my first and maybe only patch in this official new role, because this driver is otherwise bug-free :-) Alan: "Actually its also a bug fix, tty->ldisc should be locked by refcounting and the helpers do this for you." Signed-off-by: Linas Vepstas Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/hvsi.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/char/hvsi.c') diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c index 54cbb58b8740..017f755632a3 100644 --- a/drivers/char/hvsi.c +++ b/drivers/char/hvsi.c @@ -987,10 +987,7 @@ static void hvsi_write_worker(void *arg) start_j = 0; #endif /* DEBUG */ wake_up_all(&hp->emptyq); - if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags) - && hp->tty->ldisc.write_wakeup) - hp->tty->ldisc.write_wakeup(hp->tty); - wake_up_interruptible(&hp->tty->write_wait); + tty_wakeup(hp->tty); } out: -- cgit v1.2.3