From: Nathael Pajani Date: Thu, 2 Sep 2010 14:06:16 +0000 (+0200) Subject: tty: fix tty_line must not be equal to number of allocated tty pointers in tty driver X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6eb68d6f3bf1707d5d816ea9242b7d38f25b942e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git tty: fix tty_line must not be equal to number of allocated tty pointers in tty driver I found a bug "by chance" in drivers/char/tty_io.c I mean "by chance" because I was just reading the code of the tty_find_polling_driver() to make a new tty_find_by_name() function. In tty_find_polling_driver() the driver actually test "tty_line <= p->num" while num refers to the number of struct tty_struct pointers allocated for the p->ttys (p is a tty_driver), and tty_line is scanned in a tty name, which can be for example ttyS2. Then tty_line equals 2. And if p->num is 2, we have only p->ttys[0] and p->ttys[1], but no p->ttys[2]. This is actually unharmful, for tty_find_polling_driver() is used only in drivers/serial/kgdboc.c, and there's a test over there to find a console with a matching index, which will never happen. This is still a bug anyway. Signed-off-by: Nathael Pajani Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 949067a0bd47..613c852ee0fe 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -355,7 +355,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) if (*stp == '\0') stp = NULL; - if (tty_line >= 0 && tty_line <= p->num && p->ops && + if (tty_line >= 0 && tty_line < p->num && p->ops && p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { res = tty_driver_kref_get(p); *line = tty_line;