This is a note to let you know that I've just added the patch titled
tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From b8caf69a6946e18ffebad49847e258f5b6d52ac2 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Date: Wed, 21 Dec 2022 17:40:22 +0100
Subject: tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO
buffer
Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on
default RX FIFO depth, e.g. 16. Later during serial startup the
qcom_geni_serial_port_setup() updates the RX FIFO depth
(port->rx_fifo_depth) to match real device capabilities, e.g. to 32.
The RX UART handle code will read "port->rx_fifo_depth" number of words
into "port->rx_fifo" buffer, thus exceeding the bounds. This can be
observed in certain configurations with Qualcomm Bluetooth HCI UART
device and KASAN:
Bluetooth: hci0: QCA Product ID :0x00000010
Bluetooth: hci0: QCA SOC Version :0x400a0200
Bluetooth: hci0: QCA ROM Version :0x00000200
Bluetooth: hci0: QCA Patch Version:0x00000d2b
Bluetooth: hci0: QCA controller version 0x02000200
Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv
bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2
Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2)
Bluetooth: hci0: QCA Failed to download patch (-2)
==================================================================
BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c
Write of size 4 at addr ffff279347d578c0 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
dump_backtrace.part.0+0xe0/0xf0
show_stack+0x18/0x40
dump_stack_lvl+0x8c/0xb8
print_report+0x188/0x488
kasan_report+0xb4/0x100
__asan_store4+0x80/0xa4
handle_rx_uart+0xa8/0x18c
qcom_geni_serial_handle_rx+0x84/0x9c
qcom_geni_serial_isr+0x24c/0x760
__handle_irq_event_percpu+0x108/0x500
handle_irq_event+0x6c/0x110
handle_fasteoi_irq+0x138/0x2cc
generic_handle_domain_irq+0x48/0x64
If the RX FIFO depth changes after probe, be sure to resize the buffer.
Fixes: f9d690b6ece7 ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Reviewed-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221221164022.1087814-1-krzysztof.kozlowski@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/qcom_geni_serial.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index b487823f0e61..49b9ffeae676 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -864,9 +864,10 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
return IRQ_HANDLED;
}
-static void get_tx_fifo_size(struct qcom_geni_serial_port *port)
+static int setup_fifos(struct qcom_geni_serial_port *port)
{
struct uart_port *uport;
+ u32 old_rx_fifo_depth = port->rx_fifo_depth;
uport = &port->uport;
port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
@@ -874,6 +875,16 @@ static void get_tx_fifo_size(struct qcom_geni_serial_port *port)
port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
uport->fifosize =
(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
+
+ if (port->rx_fifo && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
+ port->rx_fifo = devm_krealloc(uport->dev, port->rx_fifo,
+ port->rx_fifo_depth * sizeof(u32),
+ GFP_KERNEL);
+ if (!port->rx_fifo)
+ return -ENOMEM;
+ }
+
+ return 0;
}
@@ -888,6 +899,7 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
u32 proto;
u32 pin_swap;
+ int ret;
proto = geni_se_read_proto(&port->se);
if (proto != GENI_SE_UART) {
@@ -897,7 +909,9 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
qcom_geni_serial_stop_rx(uport);
- get_tx_fifo_size(port);
+ ret = setup_fifos(port);
+ if (ret)
+ return ret;
writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
--
2.39.1
