From 6eabce6608d6f3440f4c03aa3d3ef50a47a3d193 Mon Sep 17 00:00:00 2001 From: George Kennedy Date: Wed, 17 Jul 2024 07:24:38 -0500 Subject: [PATCH 1/4] serial: core: check uartclk for zero to avoid divide by zero Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Reported-by: syzkaller Cc: stable@vger.kernel.org Signed-off-by: George Kennedy Rule: add Link: https://lore.kernel.org/stable/1721148848-9784-1-git-send-email-george.kennedy%40oracle.com Link: https://lore.kernel.org/r/1721219078-3209-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 9a18d0b95a419..5bea3af46abce 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -881,6 +881,14 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, new_flags = (__force upf_t)new_info->flags; old_custom_divisor = uport->custom_divisor; + if (!(uport->flags & UPF_FIXED_PORT)) { + unsigned int uartclk = new_info->baud_base * 16; + /* check needs to be done here before other settings made */ + if (uartclk == 0) { + retval = -EINVAL; + goto exit; + } + } if (!capable(CAP_SYS_ADMIN)) { retval = -EPERM; if (change_irq || change_port || From 133f4c00b8b2bfcacead9b81e7e8edfceb4b06c4 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Tue, 23 Jul 2024 08:53:00 -0400 Subject: [PATCH 2/4] serial: sc16is7xx: fix TX fifo corruption Sometimes, when a packet is received on channel A at almost the same time as a packet is about to be transmitted on channel B, we observe with a logic analyzer that the received packet on channel A is transmitted on channel B. In other words, the Tx buffer data on channel B is corrupted with data from channel A. The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels"), which changed the EFR locking to operate on each channel instead of chip-wise. This commit has introduced a regression, because the EFR lock is used not only to protect the EFR registers access, but also, in a very obscure and undocumented way, to protect access to the data buffer, which is shared by the Tx and Rx handlers, but also by each channel of the IC. Fix this regression first by switching to kfifo_out_linear_ptr() in sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer. Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for each channel. Fixes: 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240723125302.1305372-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sc16is7xx.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index c79dcd7c8d1a6..58696e05492ca 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -327,6 +327,7 @@ struct sc16is7xx_one { struct kthread_work reg_work; struct kthread_delayed_work ms_work; struct sc16is7xx_one_config config; + unsigned char buf[SC16IS7XX_FIFO_SIZE]; /* Rx buffer. */ unsigned int old_mctrl; u8 old_lcr; /* Value before EFR access. */ bool irda_mode; @@ -340,7 +341,6 @@ struct sc16is7xx_port { unsigned long gpio_valid_mask; #endif u8 mctrl_mask; - unsigned char buf[SC16IS7XX_FIFO_SIZE]; struct kthread_worker kworker; struct task_struct *kworker_task; struct sc16is7xx_one p[]; @@ -612,18 +612,18 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, unsigned int iir) { - struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); unsigned int lsr = 0, bytes_read, i; bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false; u8 ch, flag; - if (unlikely(rxlen >= sizeof(s->buf))) { + if (unlikely(rxlen >= sizeof(one->buf))) { dev_warn_ratelimited(port->dev, "ttySC%i: Possible RX FIFO overrun: %d\n", port->line, rxlen); port->icount.buf_overrun++; /* Ensure sanity of RX level */ - rxlen = sizeof(s->buf); + rxlen = sizeof(one->buf); } while (rxlen) { @@ -636,10 +636,10 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, lsr = 0; if (read_lsr) { - s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG); + one->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG); bytes_read = 1; } else { - sc16is7xx_fifo_read(port, s->buf, rxlen); + sc16is7xx_fifo_read(port, one->buf, rxlen); bytes_read = rxlen; } @@ -672,7 +672,7 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, } for (i = 0; i < bytes_read; ++i) { - ch = s->buf[i]; + ch = one->buf[i]; if (uart_handle_sysrq_char(port, ch)) continue; @@ -690,10 +690,10 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, static void sc16is7xx_handle_tx(struct uart_port *port) { - struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct tty_port *tport = &port->state->port; unsigned long flags; unsigned int txlen; + unsigned char *tail; if (unlikely(port->x_char)) { sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char); @@ -718,8 +718,9 @@ static void sc16is7xx_handle_tx(struct uart_port *port) txlen = 0; } - txlen = uart_fifo_out(port, s->buf, txlen); - sc16is7xx_fifo_write(port, s->buf, txlen); + txlen = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen); + sc16is7xx_fifo_write(port, tail, txlen); + uart_xmit_advance(port, txlen); uart_port_lock_irqsave(port, &flags); if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) From 7d3b793faaab1305994ce568b59d61927235f57b Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Tue, 23 Jul 2024 08:53:01 -0400 Subject: [PATCH 3/4] serial: sc16is7xx: fix invalid FIFO access with special register set When enabling access to the special register set, Receiver time-out and RHR interrupts can happen. In this case, the IRQ handler will try to read from the FIFO thru the RHR register at address 0x00, but address 0x00 is mapped to DLL register, resulting in erroneous FIFO reading. Call graph example: sc16is7xx_startup(): entry sc16is7xx_ms_proc(): entry sc16is7xx_set_termios(): entry sc16is7xx_set_baud(): DLH/DLL = $009C --> access special register set sc16is7xx_port_irq() entry --> IIR is 0x0C sc16is7xx_handle_rx() entry sc16is7xx_fifo_read(): --> unable to access FIFO (RHR) because it is mapped to DLL (LCR=LCR_CONF_MODE_A) sc16is7xx_set_baud(): exit --> Restore access to general register set Fix the problem by claiming the efr_lock mutex when accessing the Special register set. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240723125302.1305372-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sc16is7xx.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 58696e05492ca..b4c1798a1df2a 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -592,6 +592,8 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_MCR_CLKSEL_BIT, prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); + mutex_lock(&one->efr_lock); + /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, @@ -606,6 +608,8 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); + mutex_unlock(&one->efr_lock); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } From 6e20753da6bc651e02378a0cdb78f16c42098c88 Mon Sep 17 00:00:00 2001 From: Max Krummenacher Date: Thu, 25 Jul 2024 15:20:45 +0200 Subject: [PATCH 4/4] tty: vt: conmakehash: cope with abs_srctree no longer in env conmakehash uses getenv("abs_srctree") from the environment to strip the absolute path from the generated sources. However since commit e2bad142bb3d ("kbuild: unexport abs_srctree and abs_objtree") this environment variable no longer gets set. Instead use basename() to indicate the used file in a comment of the generated source file. Fixes: 3bd85c6c97b2 ("tty: vt: conmakehash: Don't mention the full path of the input in output") Cc: stable Signed-off-by: Max Krummenacher Link: https://lore.kernel.org/stable/20240725132056.9151-1-max.oss.09%40gmail.com Link: https://lore.kernel.org/r/20240725132056.9151-1-max.oss.09@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/conmakehash.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/drivers/tty/vt/conmakehash.c b/drivers/tty/vt/conmakehash.c index dc2177fec7156..82d9db68b2ce8 100644 --- a/drivers/tty/vt/conmakehash.c +++ b/drivers/tty/vt/conmakehash.c @@ -11,6 +11,8 @@ * Copyright (C) 1995-1997 H. Peter Anvin */ +#include +#include #include #include #include @@ -76,8 +78,8 @@ static void addpair(int fp, int un) int main(int argc, char *argv[]) { FILE *ctbl; - const char *tblname, *rel_tblname; - const char *abs_srctree; + const char *tblname; + char base_tblname[PATH_MAX]; char buffer[65536]; int fontlen; int i, nuni, nent; @@ -102,16 +104,6 @@ int main(int argc, char *argv[]) } } - abs_srctree = getenv("abs_srctree"); - if (abs_srctree && !strncmp(abs_srctree, tblname, strlen(abs_srctree))) - { - rel_tblname = tblname + strlen(abs_srctree); - while (*rel_tblname == '/') - ++rel_tblname; - } - else - rel_tblname = tblname; - /* For now we assume the default font is always 256 characters. */ fontlen = 256; @@ -253,6 +245,8 @@ int main(int argc, char *argv[]) for ( i = 0 ; i < fontlen ; i++ ) nuni += unicount[i]; + strncpy(base_tblname, tblname, PATH_MAX); + base_tblname[PATH_MAX - 1] = 0; printf("\ /*\n\ * Do not edit this file; it was automatically generated by\n\ @@ -264,7 +258,7 @@ int main(int argc, char *argv[]) #include \n\ \n\ u8 dfont_unicount[%d] = \n\ -{\n\t", rel_tblname, fontlen); +{\n\t", basename(base_tblname), fontlen); for ( i = 0 ; i < fontlen ; i++ ) {