linux/drivers/tty
Krzysztof Kozlowski e51e4d8a18 serial: samsung: Fix ERR pointer dereference on deferred probe
When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe
finishes with success but uses invalid (ERR_PTR) values.  This leads to
dereferencing of ERR_PTR stored under ourport->clk:

	12c30000.serial: Controller clock not found
	(...)
	12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10
	Unable to handle kernel paging request at virtual address fffffdfb

	(clk_prepare) from [<c039f7d0>] (s3c24xx_serial_pm+0x20/0x128)
	(s3c24xx_serial_pm) from [<c0395414>] (uart_change_pm+0x38/0x40)
	(uart_change_pm) from [<c039689c>] (uart_add_one_port+0x31c/0x44c)
	(uart_add_one_port) from [<c03a035c>] (s3c24xx_serial_probe+0x2a8/0x418)
	(s3c24xx_serial_probe) from [<c03ee110>] (platform_drv_probe+0x50/0xb0)
	(platform_drv_probe) from [<c03ecb44>] (driver_probe_device+0x1f4/0x2b0)
	(driver_probe_device) from [<c03eb0c0>] (bus_for_each_drv+0x44/0x8c)
	(bus_for_each_drv) from [<c03ec8c8>] (__device_attach+0x9c/0x100)
	(__device_attach) from [<c03ebf54>] (bus_probe_device+0x84/0x8c)
	(bus_probe_device) from [<c03ec388>] (deferred_probe_work_func+0x60/0x8c)
	(deferred_probe_work_func) from [<c012fee4>] (process_one_work+0x120/0x328)
	(process_one_work) from [<c0130150>] (worker_thread+0x2c/0x4ac)
	(worker_thread) from [<c0135320>] (kthread+0xd8/0xf4)
	(kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)

The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to
exit with failure but the s3c24xx_uart_port is left half-configured
(e.g. port->mapbase is set, clk contains ERR_PTR).  On next re-probe,
the function s3c24xx_serial_init_port() will exit early with success
because of configured port->mapbase and driver will use old values,
including the ERR_PTR as clock.

Fix this by cleaning the port->mapbase on error path so each re-probe
will initialize all of the port settings.

Fixes: 60e9357547 ("serial: samsung: enable clock before clearing pending interrupts during init")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 13:50:53 -07:00
..
hvc tty: hvc_console: silence unintialized variable warning 2016-04-30 09:26:55 -07:00
ipwireless tty: ipwireless, cleanup TIOCGSERIAL 2016-06-25 08:56:30 -07:00
serial serial: samsung: Fix ERR pointer dereference on deferred probe 2016-06-25 13:50:53 -07:00
vt tty/vt/keyboard: use memdup_user(). 2016-06-25 10:40:33 -07:00
amiserial.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
bfin_jtag_comm.c
cyclades.c tty: stop defining STD_COM_FLAGS in drivers 2016-06-25 08:56:30 -07:00
ehv_bytechan.c drivers/tty: make ehv_bytechan.c explicitly non-modular 2016-02-06 23:26:43 -08:00
goldfish.c tty: goldfish: support platform_device with id -1 2016-03-07 16:11:14 -08:00
isicom.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
Kconfig devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
Makefile
metag_da.c
mips_ejtag_fdc.c
moxa.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
moxa.h
mxser.c tty: cyclades+mxser, do not initialize to zero 2016-06-25 08:56:30 -07:00
mxser.h
n_gsm.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
n_hdlc.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
nozomi.c tty: Replace TTY_THROTTLED bit tests with tty_throttled() 2016-04-30 09:26:55 -07:00
pty.c devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
rocket_int.h
rocket.c TTY: add __init attribute 2016-04-30 09:26:55 -07:00
rocket.h
synclink_gt.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
synclink.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
synclinkmp.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
sysrq.c
tty_audit.c tty: audit: remove unused variable 2016-03-07 16:11:14 -08:00
tty_buffer.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
tty_io.c Merge 4.6-rc7 into tty-next 2016-05-09 09:39:13 +02:00
tty_ioctl.c tty: Replace TTY_THROTTLED bit tests with tty_throttled() 2016-04-30 09:26:55 -07:00
tty_ldisc.c
tty_ldsem.c
tty_mutex.c Merge 4.5-rc4 into tty-next 2016-02-14 14:36:04 -08:00
tty_port.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00