George Kennedy e3ad503876 serial: core: check uartclk for zero to avoid divide by zero ... commit 6eabce6608 upstream. 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: <TASK> 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 <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: George Kennedy <george.kennedy@oracle.com> 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 <gregkh@linuxfoundation.org>		2024-08-14 13:58:57 +02:00
..
hvc
ipwireless
serdev
serial	serial: core: check uartclk for zero to avoid divide by zero	2024-08-14 13:58:57 +02:00
vt	tty: add the option to have a tty reject a new ldisc	2024-06-27 13:49:05 +02:00
amiserial.c
ehv_bytechan.c
goldfish.c
Kconfig
Makefile
mips_ejtag_fdc.c
moxa.c
mxser.c
n_gsm.c	tty: n_gsm: fix missing receive state reset after mode switch	2024-06-12 11:11:18 +02:00
n_hdlc.c
n_null.c
n_tty.c	tty: n_tty: Fix buffer offsets when lookahead is used	2024-06-21 14:38:24 +02:00
nozomi.c
pty.c
rpmsg_tty.c
synclink_gt.c
sysrq.c
tty.h
tty_audit.c
tty_baudrate.c
tty_buffer.c
tty_io.c	usb: cdc-acm: return correct error code on unsupported break	2024-01-25 15:35:53 -08:00
tty_ioctl.c	tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE	2024-02-05 20:14:32 +00:00
tty_jobctrl.c
tty_ldisc.c	tty: add the option to have a tty reject a new ldisc	2024-06-27 13:49:05 +02:00
tty_ldsem.c
tty_mutex.c
tty_port.c
ttynull.c
vcc.c