kernel/linux.git/drivers/tty, branch v4.4.8

8250: use callbacks to access UART_DLL/UART_DLM

2016-04-12T16:08:49+00:00

commit 0b41ce991052022c030fd868e03877700220b090 upstream. Some UART HW has a single register combining UART_DLL/UART_DLM (this was probably forgotten in the change that introduced the callbacks, commit b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9) Fixes: b32b19b8ffc0 ("[SERIAL] 8250: set divisor register correctly ...") Signed-off-by: Sebastian Frias Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)

2016-02-25T20:01:14+00:00

commit 308bbc9ab838d0ace0298268c7970ba9513e2c65 upstream. The omap-serial driver emulates RS485 delays using software timers, but neglects to clamp the input values from the unprivileged ioctl(TIOCSRS485). Because the software implementation busy-waits, malicious userspace could stall the cpu for ~49 days. Clamp the input values to < 100ms. Fixes: 4a0ac0f55b18 ("OMAP: add RS485 support") Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Add Intel Broadwell ports

2016-02-25T20:01:14+00:00

commit 6c55d9b98335f7f6bd5f061866ff1633401f3a44 upstream. Some recent (early 2015) macbooks have Intel Broadwell where LPSS UARTs are PCI enumerated instead of ACPI. The LPSS UART block is pretty much same as used on Intel Baytrail so we can reuse the existing Baytrail setup code. Add both Broadwell LPSS UART ports to the list of supported devices. Signed-off-by: Leif Liddy Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman

tty: Add support for PCIe WCH382 2S multi-IO card

2016-02-25T20:01:14+00:00

commit 7dde55787b43a8f2b4021916db38d90c03a2ec64 upstream. WCH382 2S board is a PCIe card with 2 DB9 COM ports detected as Serial controller: Device 1c00:3253 (rev 10) (prog-if 05 [16850]) Signed-off-by: Jeremy McNicoll Signed-off-by: Greg Kroah-Hartman

pty: make sure super_block is still valid in final /dev/tty close

2016-02-25T20:01:14+00:00

commit 1f55c718c290616889c04946864a13ef30f64929 upstream. Considering current pty code and multiple devpts instances, it's possible to umount a devpts file system while a program still has /dev/tty opened pointing to a previosuly closed pty pair in that instance. In the case all ptmx and pts/N files are closed, umount can be done. If the program closes /dev/tty after umount is done, devpts_kill_index will use now an invalid super_block, which was already destroyed in the umount operation after running ->kill_sb. This is another "use after free" type of issue, but now related to the allocated super_block instance. To avoid the problem (warning at ida_remove and potential crashes) for this specific case, I added two functions in devpts which grabs additional references to the super_block, which pty code now uses so it makes sure the super block structure is still valid until pty shutdown is done. I also moved the additional inode references to the same functions, which also covered similar case with inode being freed before /dev/tty final close/shutdown. Signed-off-by: Herton R. Krzesinski Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

pty: fix possible use after free of tty->driver_data

2016-02-25T20:01:14+00:00

commit 2831c89f42dcde440cfdccb9fee9f42d54bbc1ef upstream. This change fixes a bug for a corner case where we have the the last release from a pty master/slave coming from a previously opened /dev/tty file. When this happens, the tty->driver_data can be stale, due to all ptmx or pts/N files having already been closed before (and thus the inode related to these files, which tty->driver_data points to, being already freed/destroyed). The fix here is to keep a reference on the opened master ptmx inode. We maintain the inode referenced until the final pty_unix98_shutdown, and only pass this inode to devpts_kill_index. Signed-off-by: Herton R. Krzesinski Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)

2016-02-17T20:31:02+00:00

commit 5c17c861a357e9458001f021a7afa7aab9937439 upstream. ioctl(TIOCGETD) retrieves the line discipline id directly from the ldisc because the line discipline id (c_line) in termios is untrustworthy; userspace may have set termios via ioctl(TCSETS*) without actually changing the line discipline via ioctl(TIOCSETD). However, directly accessing the current ldisc via tty->ldisc is unsafe; the ldisc ptr dereferenced may be stale if the line discipline is changing via ioctl(TIOCSETD) or hangup. Wait for the line discipline reference (just like read() or write()) to retrieve the "current" line discipline id. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Retry failed reopen if tty teardown in-progress

2016-02-17T20:31:02+00:00

commit 7f22f6c935cda600660e623a411fe380015d28d9 upstream. A small window exists where a tty reopen will observe the tty just prior to imminent teardown (tty->count == 0); in this case, open() returns EIO to userspace. Instead, retry the open after checking for signals and yielding; this interruptible retry loop allows teardown to commence and initialize a new tty on retry. Never retry the BSD master pty reopen; there is no guarantee the pty pair teardown is imminent since the slave file descriptors may remain open indefinitely. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Wait interruptibly for tty lock on reopen

2016-02-17T20:31:02+00:00

commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream. Allow a signal to interrupt the wait for a tty reopen; eg., if the tty has starting final close and is waiting for the device to drain. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

n_tty: Fix unsafe reference to "other" ldisc

2016-02-17T20:31:02+00:00

commit 6d27a63caad3f13e96cf065d2d96828c2006be6b upstream. Although n_tty_check_unthrottle() has a valid ldisc reference (since the tty core gets the ldisc ref in tty_read() before calling the line discipline read() method), it does not have a valid ldisc reference to the "other" pty of a pty pair. Since getting an ldisc reference for tty->link essentially open-codes tty_wakeup(), just replace with the equivalent tty_wakeup(). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman