diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-04-05 19:40:16 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-01 15:13:05 -0700 |
| commit | 6a506d48c187e621ca846b6c5b951411d5b7f531 (patch) | |
| tree | dde333d7d25a5f1016f748300fd066bafa55f382 | |
| parent | 97f54c13b6aaa49eeb9688e851d1ff955f45f5c3 (diff) | |
tty: Don't call panic() at tty_ldisc_init()
commit 903f9db10f18f735e62ba447147b6c434b6af003 upstream.
syzbot is reporting kernel panic [1] triggered by memory allocation failure
at tty_ldisc_get() from tty_ldisc_init(). But since both tty_ldisc_get()
and caller of tty_ldisc_init() can cleanly handle errors, tty_ldisc_init()
does not need to call panic() when tty_ldisc_get() failed.
[1] https://syzkaller.appspot.com/bug?id=883431818e036ae6a9981156a64b821110f39187
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 5 | ||||
| -rw-r--r-- | drivers/tty/tty_ldisc.c | 5 | ||||
| -rw-r--r-- | include/linux/tty.h | 2 |
3 files changed, 8 insertions, 4 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 4ee0a9de7556..789c81482542 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3170,7 +3170,10 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) kref_init(&tty->kref); tty->magic = TTY_MAGIC; - tty_ldisc_init(tty); + if (tty_ldisc_init(tty)) { + kfree(tty); + return NULL; + } tty->session = NULL; tty->pgrp = NULL; mutex_init(&tty->legacy_mutex); diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 3a9e2a2fd4c6..96f0d1090888 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -753,12 +753,13 @@ void tty_ldisc_release(struct tty_struct *tty) * the tty structure is not completely set up when this call is made. */ -void tty_ldisc_init(struct tty_struct *tty) +int tty_ldisc_init(struct tty_struct *tty) { struct tty_ldisc *ld = tty_ldisc_get(tty, N_TTY); if (IS_ERR(ld)) - panic("n_tty: init_tty"); + return PTR_ERR(ld); tty->ldisc = ld; + return 0; } /** diff --git a/include/linux/tty.h b/include/linux/tty.h index 6f1ee8528210..fe1b8623a3a1 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -657,7 +657,7 @@ extern int tty_unregister_ldisc(int disc); extern int tty_set_ldisc(struct tty_struct *tty, int disc); extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); extern void tty_ldisc_release(struct tty_struct *tty); -extern void tty_ldisc_init(struct tty_struct *tty); +extern int __must_check tty_ldisc_init(struct tty_struct *tty); extern void tty_ldisc_deinit(struct tty_struct *tty); extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p, char *f, int count); |