2008-11-20 15:01:38

by Will Newton

[permalink] [raw]
Subject: [PATCH] drivers/char/tty_io.c: Avoid panic when no console is configured.

When no console is configured tty_open tries to call kref_get on a NULL
pointer, return ENODEV instead.

Signed-off-by: Will Newton <[email protected]>
---
drivers/char/tty_io.c | 15 +++++++++------
1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 59f4721..1412a8d 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1795,12 +1795,15 @@ retry_open:
}
#endif
if (device == MKDEV(TTYAUX_MAJOR, 1)) {
- driver = tty_driver_kref_get(console_device(&index));
- if (driver) {
- /* Don't let /dev/console block */
- filp->f_flags |= O_NONBLOCK;
- noctty = 1;
- goto got_driver;
+ struct tty_driver *console_driver = console_device(&index);
+ if (console_driver) {
+ driver = tty_driver_kref_get(console_driver);
+ if (driver) {
+ /* Don't let /dev/console block */
+ filp->f_flags |= O_NONBLOCK;
+ noctty = 1;
+ goto got_driver;
+ }
}
mutex_unlock(&tty_mutex);
return -ENODEV;
--
1.5.5.2


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0001-drivers-char-tty_io.c-Avoid-panic-when-no-console-i.patch (1.22 kB)
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