| Message ID | 20221220161530.2098299-1-krzysztof.kozlowski@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO buffer | expand |
On 20. 12. 22, 17:15, Krzysztof Kozlowski wrote: > 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. ... > 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@vger.kernel.org> > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> This patch LGTM, I only wonder: > --- 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 get_tx_fifo_size(struct qcom_geni_serial_port *port) ... why is this function dubbed get_tx_fifo_size(), provided it handles rx fifo too? And it does not "get" the tx fifo size. In fact, the function sets that :). > { > 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); And now it even allocates memory. So more appropriate name should be setup_fifos() or similar. > + if (!port->rx_fifo) > + return -ENOMEM; > + } > + > + return 0;
On 21/12/2022 07:43, Jiri Slaby wrote: > On 20. 12. 22, 17:15, Krzysztof Kozlowski wrote: >> 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. > ... >> 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@vger.kernel.org> >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > > Reviewed-by: Jiri Slaby <jirislaby@kernel.org> > > This patch LGTM, I only wonder: > >> --- 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 get_tx_fifo_size(struct qcom_geni_serial_port *port) > > ... why is this function dubbed get_tx_fifo_size(), provided it handles > rx fifo too? And it does not "get" the tx fifo size. In fact, the > function sets that :). I reads the FIFO sizes from the device registers, so I guess that was behind the naming. > >> { >> 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); > > And now it even allocates memory. > > So more appropriate name should be setup_fifos() or similar. Sure, I'll rename it and keep your Rb tag. > Best regards, Krzysztof
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index b487823f0e61..1568fe69e3e8 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 get_tx_fifo_size(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 = get_tx_fifo_size(port); + if (ret) + return ret; writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
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@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> --- drivers/tty/serial/qcom_geni_serial.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)