From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793802221; b=G9otkp/xrQ62a+yqqGxHHTggLn8KdcEIibd2o4Fltb5EolvuZlGtP78xykanjl6GGUBm zn+94vfU2nlL/I2CXIxLg9E+hRV53o71vjMcOXh2FFnokG1M6p62a/0cGBoKA0ljeU1Im fxJor1BfQX6bVp2PAnbRs0Mp5G+6WFVaKN1lpMlNB3H1WZGDI2JhUPOnAJ8id16MOzaww AnAnya7YWbsuWbpLK8j6p8siS1Nl5cSmgcbdrNdo0wONw3yboPZpETmpZRbMl8g8w0T94 V5HI54o8JstEAn8iXl/fnU89XPX1/DB2ECdtEVn9a2yJOrNcd1pGY9jCn9JXFw1ppXQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793802221; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=F7EwJsmj18W0pUfMqXmJj65rq5RvHfF0di84ScosGFo=; b=XUZtEHkECYyWc5GRN43ZYntawXyoeMdlz2OsMQW+QrQIlXHTQwncz94mC3SugU/Jv4Pp RzJ/ZHaYARHp+1iMnXiWNfvsNupDHSgZDEXawXsBHsMv4ZQ8lCsNxtHbFEE8T77HmfW7d Z61hoJwH7CnTjOWL5x5ehtrHDF/DHBJ3TwTpHy5eT64ROnsgrRAlO62k+9qbHKp7Q0rlT sV711dlSQ49T0N8tdb7QXzJ7EIGGA8hlCh/V73FTxpXxANQ1fpmNtjGd0ATb6MqjKREYF jBCCHt2lyav/PZSImNE0b1oDSXKzFkIkMcB7PJlyl97kvKDxjJKq2xkWyLU8kZfW5Xw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=a4CH3lJq; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C8EB7606A31B for ; Wed, 4 Nov 2026 14:23:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=a4CH3lJq Received: by smtp.kernel.org (Postfix) with ESMTPSA id D679F1F000C1; Wed, 4 Nov 2026 14:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793802220; bh=F7EwJsmj18W0pUfMqXmJj65rq5RvHfF0di84ScosGFo=; h=Subject:To:Cc:From:Date; b=a4CH3lJqUF8shvbV8wraMnB4Q6gdbT/8gPzEgOwmVwNpCt4Z16sYR03VvP89yUTt7 3sCQAjIH+WFpUrusBgsPOVoU80bLDEy7kJlYpf9eG7w4hq0DXgmjz9T5GqYl0FXbQA ZUuNMDCGC4QRcapB5Gd96sUdrczm95X111E9y4iI= Subject: FAILED: patch "[PATCH] serial: core: shut down initialized port on removal" failed to apply to 5.15-stable tree To: igorpetindev@gmail.com,gregkh@linuxfoundation.org,stable@kernel.org Cc: From: Date: Wed, 04 Nov 2026 15:23:37 +0100 Message-ID: <2026110437-fabulous-dingbat-b644@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 810d467c11f0c85107874d08dfdd11acba6aa0c0 # git commit -s git send-email --to '' --in-reply-to '2026110437-fabulous-dingbat-b644@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 810d467c11f0c85107874d08dfdd11acba6aa0c0 Mon Sep 17 00:00:00 2001 From: Igor Putko Date: Sat, 3 Oct 2026 19:33:37 +0300 Subject: [PATCH] serial: core: shut down initialized port on removal When a serial port configured as a console is opened and subsequently closed, tty_port_shutdown() skips invoking port->ops->shutdown() because port->console is true. As a result, tty_port_initialized() remains true and the port's interrupt handler stays registered in the irq subsystem. If the underlying device is later unbound or removed (e.g. via sysfs driver unbind or device hot-unplug), serial_core_remove_one_port() unregisters the console, frees uport->name via kfree(), and tears down the port without shutting it down or freeing its IRQ. Consequently, the irqaction descriptor remains registered in genirq with action->name pointing to freed memory. This triggers a use-after-free read whenever genirq accesses action->name, such as when reading /proc/interrupts: BUG: KASAN: slab-use-after-free in string+0x476/0x570 Call Trace: string+0x476/0x570 vsnprintf+0x422/0x1300 seq_printf+0x... show_interrupts+... Fix this by acquiring port->mutex in serial_core_remove_one_port() after console unregistration, clearing port->console under the mutex to prevent data races with concurrent tty_port_shutdown(), and invoking uart_shutdown(NULL, state) if the port remains initialized. This ensures that port->ops->shutdown() is called and the IRQ is freed before kfree(uport->name). Reported-by: syzbot+843bf2f48f4d12e6682e@syzkaller.appspotmail.com Cc: stable Closes: https://syzkaller.appspot.com/bug?extid=843bf2f48f4d12e6682e Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Fixes: f7048b15900f ("tty: serial_core: Add name field to uart_port struct") Signed-off-by: Igor Putko Link: https://patch.msgid.link/20261003163337.45577-1-igorpetindev@gmail.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 319a4b427f3a..05450529871e 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3239,6 +3239,13 @@ static void serial_core_remove_one_port(struct uart_driver *drv, if (uart_console(uport)) unregister_console(uport->cons); + scoped_guard(mutex, &port->mutex) { + port->console = false; + + if (tty_port_initialized(port)) + uart_shutdown(NULL, state); + } + /* * Free the port IO and memory resources, if any. */