diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-04-05 13:40:16 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-10-21 10:45:38 +0300 |
| commit | 18b95e54fa5acf97134da61b0e5ed5af3e9f4d33 (patch) | |
| tree | c59637bfaf3a8a7f86c043c89f92bc6eec00a990 | |
| parent | 0d4116a6a63f241d6daeea90cac52cbe4d87cf2e (diff) | |
| download | linux-18b95e54fa5acf97134da61b0e5ed5af3e9f4d33.tar.xz | |
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 b49323810c53..5ab3e0b7d2a7 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3036,7 +3036,10 @@ 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 0a446ad58c53..6d8fa8e68cb7 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -820,12 +820,13 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_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 453dcc810da0..38394e5a242b 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -556,7 +556,7 @@ extern int tty_unregister_ldisc(int disc); extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_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 void tty_ldisc_begin(void); |