From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 509D05172C2 for ; Mon, 5 Oct 2026 17:18:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791220683; cv=none; b=Fs83s99UPvTCRnuOXIP97IHUmmV8btOtEiqoLv5B/dZnVT/tbV19KTOZbCC7I3NU+sDMzUQQigjrPqwyY0hTQEFpkb4PLPCNC0HaSY8vIkB6SlSK40i6ZL+4WpFI4AQRZ9gNqVQLc2XyM1lDo4/xLlJ80Bxckd4ho2eoLYYi5D4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791220683; c=relaxed/simple; bh=KwoUecnVMa3MFQCze6SSlAFVZhCBBAZK3KfrSDj4Yh8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B+Fq4gIChSLeVhm1y/JrrnZ9nQobL6QGZKk1Ij9n1RdMJq/4RYGPelVaAll92vRqvkwIrEhABOfjUnlXxsn7ufEkaH2e7/3HV479cJ3kkjUGNam+lrU609RqzIwhpzkj5kcfiIncmQ4OK+B9LCVr/8dI6rBgiBtFKg4fRxE63IY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CTkXXgMf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CTkXXgMf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9796F1F000FF; Mon, 5 Oct 2026 17:18:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791220682; bh=BxSJnjxar8g7Z+wgVngsd8/410WNVbUf8sN+wBIb8LY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CTkXXgMf2fSSePhY+1mui4he42yy5SoHBoIGqa24sFs897anr8dzkCR+CvkHkheXn Tjy/yK1ZipTngw3SP826j0EnUSo+NrSweSUsIG5AU+LlolaoSbqcP++t+P1tR47lAn cAbkxpw/0KCU4VxN95ll61/qJg30e8Gr/AKAjCftyOjt638gNu00NF+MB/KgQGsuJd rFRtxcDQxdRk5VUuHAUKj9PfpdLjTKMOjLstmOjsIkjLaAIM2B6FfNHG2TDYdXl3d/ sCx5o3sYvUQXHrFeLX1CdWEueILWwvJlf4z8BJ1AeDbiIX2hlNkT/T2HzMZrLzczFR RPEqNXbUxLNJQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Johan Hovold , stable , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.12.y 3/3] tty: tty_port: restore TTY_IO_ERROR on activation failure Date: Mon, 5 Oct 2026 13:17:54 -0400 Message-ID: <20261005171429.3065052-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261005171429.3065052-1-sashal@kernel.org> References: <2026100521-mammal-arose-32f1@gregkh> <20261005171429.3065052-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Johan Hovold [ Upstream commit 56964f6a31238fb41d5830bb42520c5b10ff7d8f ] Make sure to restore the TTY_IO_ERROR flag if activation fails to prevent I/O attempts on a port that is gone or powered down. This specifically avoids issues like kernel panic due to unclocked accesses or NULL-pointer dereferences when accessing powered down or deregistered ports when a TTY ioctl races with hangup and open. Note that the flag is set again in tty_port_close() but not restoring it on activation failure leaves a window where drivers fail to handle the ioctl-hangup race. Fixes: a9a37ec33a1b ("tty: tty_port: Move the IO_ERROR clear") Cc: stable # 2.6.33 Signed-off-by: Johan Hovold Link: https://patch.msgid.link/20260908084000.218528-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/tty_port.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c index 64b2584ff7a18..10d707e3c0344 100644 --- a/drivers/tty/tty_port.c +++ b/drivers/tty/tty_port.c @@ -765,8 +765,10 @@ int tty_port_open(struct tty_port *port, struct tty_struct *tty, clear_bit(TTY_IO_ERROR, &tty->flags); if (port->ops->activate) { int retval = port->ops->activate(port, tty); - if (retval) + if (retval) { + set_bit(TTY_IO_ERROR, &tty->flags); return retval; + } } tty_port_set_initialized(port, true); } -- 2.53.0