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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-20 10:46:58 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-21 17:41:02 +0100 |
| commit | 27cfb3a53be46a54ec5e0bd04e51995b74c90343 (patch) | |
| tree | 04163f2cb58466c7620882f449e0af71ff100bae /drivers/tty | |
| parent | bfd8d8fe98b8792f362cd210a7873969f8d2fc04 (diff) | |
| download | linux-27cfb3a53be46a54ec5e0bd04e51995b74c90343.tar.gz | |
tty: Handle problem if line discipline does not have receive_buf
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>
Diffstat (limited to 'drivers/tty')
| -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 23c6fd238422..21ffcce16927 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2189,7 +2189,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p) ld = tty_ldisc_ref_wait(tty); if (!ld) return -EIO; - 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; } |