hulk inclusion category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IACT4T CVE: CVE-2024-40966
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After backport mainline commit 6bd23e0c2bb6 ("tty: add the option to have a tty reject a new ldisc") Introduced kabi breakage. Fix kabi breakage by check whether it is vt device in tty_set_ldisc(), and check ldisc whether it is N_TTY.
Fixes: 6bd23e0c2bb6 ("tty: add the option to have a tty reject a new ldisc") Signed-off-by: Yi Yang yiyang13@huawei.com --- drivers/tty/tty_ldisc.c | 10 +++++++--- drivers/tty/vt/vt.c | 10 ---------- include/linux/tty_driver.h | 1 - 3 files changed, 7 insertions(+), 14 deletions(-)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index dc5267ac9923..94aa39cde22e 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -579,11 +579,15 @@ int tty_set_ldisc(struct tty_struct *tty, int disc) goto out; }
- if (tty->ops->ldisc_ok) { - retval = tty->ops->ldisc_ok(tty, disc); - if (retval) +#ifdef CONFIG_VT + /*vt device use only n_tty ldisc*/ + if (tty->ops->ioctl == vt_ioctl) { + if (disc != N_TTY) { + retval = -EINVAL; goto out; + } } +#endif
old_ldisc = tty->ldisc;
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 34f3f752f0b2..33fb7b6555f4 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3448,15 +3448,6 @@ static void con_cleanup(struct tty_struct *tty) tty_port_put(&vc->port); }
-/* - * We can't deal with anything but the N_TTY ldisc, - * because we can sleep in our write() routine. - */ -static int con_ldisc_ok(struct tty_struct *tty, int ldisc) -{ - return ldisc == N_TTY ? 0 : -EINVAL; -} - static int default_color = 7; /* white */ static int default_italic_color = 2; // green (ASCII) static int default_underline_color = 3; // cyan (ASCII) @@ -3585,7 +3576,6 @@ static const struct tty_operations con_ops = { .resize = vt_resize, .shutdown = con_shutdown, .cleanup = con_cleanup, - .ldisc_ok = con_ldisc_ok, };
static struct cdev vc0_cdev; diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index c80e82a93577..2f719b471d52 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -256,7 +256,6 @@ struct tty_operations { const unsigned char *buf, int count); int (*put_char)(struct tty_struct *tty, unsigned char ch); void (*flush_chars)(struct tty_struct *tty); - int (*ldisc_ok)(struct tty_struct *tty, int ldisc); int (*write_room)(struct tty_struct *tty); int (*chars_in_buffer)(struct tty_struct *tty); int (*ioctl)(struct tty_struct *tty,