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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-20 12:46:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-06 21:43:04 +0300 |
| commit | fe881381874a2dd2b790ffe5399aaa2b1ed51bc9 (patch) | |
| tree | 4e8c7df4a2ae1fcf879472f406c104b34d34580e | |
| parent | b6a23bda233ae5dce88f48108016d545c7e84e01 (diff) | |
| download | linux-fe881381874a2dd2b790ffe5399aaa2b1ed51bc9.tar.xz | |
tty: Handle problem if line discipline does not have receive_buf
commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream.
Some tty line disciplines do not have a receive buf callback, so
properly check for that before calling it. If they do not have this
callback, just eat the character quietly, as we can't fail this call.
Reported-by: Jann Horn <jannh@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index c1cff2b455ae..5b86ebc76a8a 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2297,7 +2297,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p) return -EFAULT; tty_audit_tiocsti(tty, ch); ld = tty_ldisc_ref_wait(tty); - ld->ops->receive_buf(tty, &ch, &mbz, 1); + if (ld->ops->receive_buf) + ld->ops->receive_buf(tty, &ch, &mbz, 1); tty_ldisc_deref(ld); return 0; } |