linux-kernel - [PATCH 5.4 115/138] serial: tegra: fix CREAD handling for PIO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200727134931.199769367@linuxfoundation.org>
Date:   Mon, 27 Jul 2020 16:05:10 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Shardar Shariff Md <smohammed@...dia.com>,
        Krishna Yarlagadda <kyarlagadda@...dia.com>,
        Johan Hovold <johan@...nel.org>,
        Thierry Reding <treding@...dia.com>
Subject: [PATCH 5.4 115/138] serial: tegra: fix CREAD handling for PIO

From: Johan Hovold <johan@...nel.org>

commit b374c562ee7ab3f3a1daf959c01868bae761571c upstream.

Commit 33ae787b74fc ("serial: tegra: add support to ignore read") added
support for dropping input in case CREAD isn't set, but for PIO the
ignore_status_mask wasn't checked until after the character had been
put in the receive buffer.

Note that the NULL tty-port test is bogus and will be removed by a
follow-on patch.

Fixes: 33ae787b74fc ("serial: tegra: add support to ignore read")
Cc: stable <stable@...r.kernel.org>     # 5.4
Cc: Shardar Shariff Md <smohammed@...dia.com>
Cc: Krishna Yarlagadda <kyarlagadda@...dia.com>
Signed-off-by: Johan Hovold <johan@...nel.org>
Acked-by: Thierry Reding <treding@...dia.com>
Link: https://lore.kernel.org/r/20200710135947.2737-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/tty/serial/serial-tegra.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -651,11 +651,14 @@ static void tegra_uart_handle_rx_pio(str
 		ch = (unsigned char) tegra_uart_read(tup, UART_RX);
 		tup->uport.icount.rx++;
 
-		if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
-			tty_insert_flip_char(tty, ch, flag);
+		if (uart_handle_sysrq_char(&tup->uport, ch))
+			continue;
 
 		if (tup->uport.ignore_status_mask & UART_LSR_DR)
 			continue;
+
+		if (tty)
+			tty_insert_flip_char(tty, ch, flag);
 	} while (1);
 }