From: Tetsuo Handa Date: Tue, 28 May 2024 15:05:53 +0000 (+0900) Subject: serial: drop debugging WARN_ON_ONCE() from uart_write() X-Git-Tag: v6.10-rc4~4^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ae01e52da244af5d650378ada1bfd2d946dc1b45;p=thirdparty%2Fkernel%2Flinux.git serial: drop debugging WARN_ON_ONCE() from uart_write() syzbot is reporting lockdep warning upon int disc = 7; ioctl(open("/dev/ttyS3", O_RDONLY), TIOCSETD, &disc); sequence. Do like what commit 5f1149d2f4bf ("serial: drop debugging WARN_ON_ONCE() from uart_put_char()") does. Reported-by: syzbot+f78380e4eae53c64125c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f78380e4eae53c64125c Signed-off-by: Tetsuo Handa Acked-by: Jiri Slaby Link: https://lore.kernel.org/r/d775ae2d-a2ac-439e-8e2b-134749f60f30@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 2c1a0254d3f4a..0c4d609766633 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -622,7 +622,7 @@ static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count) return -EL3HLT; port = uart_port_lock(state, flags); - if (WARN_ON_ONCE(!state->port.xmit_buf)) { + if (!state->port.xmit_buf) { uart_port_unlock(port, flags); return 0; }