linux-stable.git/drivers/tty, branch linux-6.14.y

serial: jsm: fix NPE during jsm_uart_port_init

2025-06-10T11:15:57+00:00

commit e3975aa899c0a3bbc10d035e699b142cd1373a71 upstream.

No device was set which caused serial_base_ctrl_add to crash.

 BUG: kernel NULL pointer dereference, address: 0000000000000050
 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1  Debian 6.12.25-1
 RIP: 0010:serial_base_ctrl_add+0x96/0x120
 Call Trace:
  
  serial_core_register_port+0x1a0/0x580
  ? __setup_irq+0x39c/0x660
  ? __kmalloc_cache_noprof+0x111/0x310
  jsm_uart_port_init+0xe8/0x180 [jsm]
  jsm_probe_one+0x1f4/0x410 [jsm]
  local_pci_probe+0x42/0x90
  pci_device_probe+0x22f/0x270
  really_probe+0xdb/0x340
  ? pm_runtime_barrier+0x54/0x90
  ? __pfx___driver_attach+0x10/0x10
  __driver_probe_device+0x78/0x110
  driver_probe_device+0x1f/0xa0
  __driver_attach+0xba/0x1c0
  bus_for_each_dev+0x8c/0xe0
  bus_add_driver+0x112/0x1f0
  driver_register+0x72/0xd0
  jsm_init_module+0x36/0xff0 [jsm]
  ? __pfx_jsm_init_module+0x10/0x10 [jsm]
  do_one_initcall+0x58/0x310
  do_init_module+0x60/0x230

Tested with Digi Neo PCIe 8 port card.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable 
Signed-off-by: Dustin Lundquist 
Link: https://lore.kernel.org/r/3f31d4f75863614655c4673027a208be78d022ec.camel@null-ptr.net
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Save and restore more registers

2025-05-29T09:13:49+00:00

[ Upstream commit 81100b9a7b0515132996d62a7a676a77676cb6e3 ]

On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there
are multiple ways to configure the requested serial speed.  If firmware
uses a different method than Linux, and if any debug info is printed
after the Bit Rate Register (SCBRR) is restored, but before termios is
reconfigured (which configures the alternative method), the system may
lock-up during resume.

Fix this by saving and restoring the contents of the BRG Frequency
Division (SCDL) and Clock Select (SCCKS) registers as well.

Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which
configures the sampling point, and the SCIFA/SCIFB's Serial Port Control
and Data Registers (SCPCR/SCPDR), which configure the optional control
flow signals.

After this, all registers that are not saved/restored are either:
  - read-only,
  - write-only,
  - status registers containing flags with clear-after-set semantics,
  - FIFO Data Count Trigger registers, which do not matter much for
    the serial console.

Fixes: 22a6984c5b5df8ea ("serial: sh-sci: Update the suspend/resume support")
Signed-off-by: Geert Uytterhoeven 
Tested-by: Claudiu Beznea 
Reviewed-by: Claudiu Beznea 
Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sh-sci: Update the suspend/resume support

2025-05-29T09:13:23+00:00

[ Upstream commit 22a6984c5b5df8eab864d7f3e8b94d5a554d31ab ]

The Renesas RZ/G3S supports a power saving mode where power to most of the
SoC components is turned off. When returning from this power saving mode,
SoC components need to be re-configured.

The SCIFs on the Renesas RZ/G3S need to be re-configured as well when
returning from this power saving mode. The sh-sci code already configures
the SCIF clocks, power domain and registers by calling uart_resume_port()
in sci_resume(). On suspend path the SCIF UART ports are suspended
accordingly (by calling uart_suspend_port() in sci_suspend()). The only
missing setting is the reset signal. For this assert/de-assert the reset
signal on driver suspend/resume.

In case the no_console_suspend is specified by the user, the registers need
to be saved on suspend path and restore on resume path. To do this the
sci_console_save()/sci_console_restore() functions were added. There is no
need to cache/restore the status or FIFO registers. Only the control
registers. The registers that will be saved/restored on suspend/resume are
specified by the struct sci_suspend_regs data structure.

Signed-off-by: Claudiu Beznea 
Reviewed-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

2025-05-29T09:13:16+00:00

[ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ]

The following splat has been observed on a SAMA5D27 platform using
atmel_serial:

BUG: sleeping function called from invalid context at kernel/irq/manage.c:738
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last  enabled at (0): [<00000000>] 0x0
hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec
softirqs last  enabled at (0): [] copy_process+0x1ca0/0x7bec
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74
Hardware name: Atmel SAMA5
Workqueue: hci0 hci_power_on [bluetooth]
Call trace:
  unwind_backtrace from show_stack+0x18/0x1c
  show_stack from dump_stack_lvl+0x44/0x70
  dump_stack_lvl from __might_resched+0x38c/0x598
  __might_resched from disable_irq+0x1c/0x48
  disable_irq from mctrl_gpio_disable_ms+0x74/0xc0
  mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4
  atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8
  atmel_set_termios from uart_change_line_settings+0x15c/0x994
  uart_change_line_settings from uart_set_termios+0x2b0/0x668
  uart_set_termios from tty_set_termios+0x600/0x8ec
  tty_set_termios from ttyport_set_flow_control+0x188/0x1e0
  ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc]
  wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth]
  hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth]
  hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth]
  hci_power_on [bluetooth] from process_one_work+0x998/0x1a38
  process_one_work from worker_thread+0x6e0/0xfb4
  worker_thread from kthread+0x3d4/0x484
  kthread from ret_from_fork+0x14/0x28

This warning is emitted when trying to toggle, at the highest level,
some flow control (with serdev_device_set_flow_control) in a device
driver. At the lowest level, the atmel_serial driver is using
serial_mctrl_gpio lib to enable/disable the corresponding IRQs
accordingly.  The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to
disable_irq (called in mctrl_gpio_disable_ms) being possibly called in
some atomic context (some tty drivers perform modem lines configuration
in regions protected by port lock).

Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one
and a blocking one. Replace mctrl_gpio_disable_ms calls with the
relevant version depending on whether the call is protected by some port
lock.

Suggested-by: Jiri Slaby 
Signed-off-by: Alexis Lothoré 
Acked-by: Richard Genoud 
Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: sifive: lock port in startup()/shutdown() callbacks

2025-05-02T06:01:52+00:00

commit e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3 upstream.

startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
The register is also accessed from write() callback.

If console were printing and startup()/shutdown() callback
gets called, its access to the register could be overwritten.

Add port->lock to startup()/shutdown() callbacks to make sure
their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
write() callback.

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Signed-off-by: Ryo Takakura 
Reviewed-by: Petr Mladek 
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness 
Rule: add
Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: msm: Configure correct working mode before starting earlycon

2025-05-02T06:01:52+00:00

commit 7094832b5ac861b0bd7ed8866c93cb15ef619996 upstream.

The MSM UART DM controller supports different working modes, e.g. DMA or
the "single-character mode", where all reads/writes operate on a single
character rather than 4 chars (32-bit) at once. When using earlycon,
__msm_console_write() always writes 4 characters at a time, but we don't
know which mode the bootloader was using and we don't set the mode either.

This causes garbled output if the bootloader was using the single-character
mode, because only every 4th character appears in the serial console, e.g.

  "[ 00oni pi  000xf0[ 00i s 5rm9(l)l s 1  1 SPMTA 7:C 5[ 00A ade k d[
   00ano:ameoi .Q1B[ 00ac _idaM00080oo'"

If the bootloader was using the DMA ("DM") mode, output would likely fail
entirely. Later, when the full serial driver probes, the port is
re-initialized and output works as expected.

Fix this also for earlycon by clearing the DMEN register and
reset+re-enable the transmitter to apply the change. This ensures the
transmitter is in the expected state before writing any output.

Cc: stable 
Fixes: 0efe72963409 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold 
Reviewed-by: Neil Armstrong 
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman

tty: Require CAP_SYS_ADMIN for all usages of TIOCL_SELMOUSEREPORT

2025-05-02T06:01:52+00:00

commit ee6a44da3c87cf64d67dd02be8c0127a5bf56175 upstream.

This requirement was overeagerly loosened in commit 2f83e38a095f
("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"), but as
it turns out,

  (1) the logic I implemented there was inconsistent (apologies!),

  (2) TIOCL_SELMOUSEREPORT might actually be a small security risk
      after all, and

  (3) TIOCL_SELMOUSEREPORT is only meant to be used by the mouse
      daemon (GPM or Consolation), which runs as CAP_SYS_ADMIN
      already.

In more detail:

1. The previous patch has inconsistent logic:

   In commit 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes
   without CAP_SYS_ADMIN"), we checked for sel_mode ==
   TIOCL_SELMOUSEREPORT, but overlooked that the lower four bits of
   this "mode" parameter were actually used as an additional way to
   pass an argument.  So the patch did actually still require
   CAP_SYS_ADMIN, if any of the mouse button bits are set, but did not
   require it if none of the mouse buttons bits are set.

   This logic is inconsistent and was not intentional.  We should have
   the same policies for using TIOCL_SELMOUSEREPORT independent of the
   value of the "hidden" mouse button argument.

   I sent a separate documentation patch to the man page list with
   more details on TIOCL_SELMOUSEREPORT:
   https://lore.kernel.org/all/20250223091342.35523-2-gnoack3000@gmail.com/

2. TIOCL_SELMOUSEREPORT is indeed a potential security risk which can
   let an attacker simulate "keyboard" input to command line
   applications on the same terminal, like TIOCSTI and some other
   TIOCLINUX "selection mode" IOCTLs.

   By enabling mouse reporting on a terminal and then injecting mouse
   reports through TIOCL_SELMOUSEREPORT, an attacker can simulate
   mouse movements on the same terminal, similar to the TIOCSTI
   keystroke injection attacks that were previously possible with
   TIOCSTI and other TIOCL_SETSEL selection modes.

   Many programs (including libreadline/bash) are then prone to
   misinterpret these mouse reports as normal keyboard input because
   they do not expect input in the X11 mouse protocol form.  The
   attacker does not have complete control over the escape sequence,
   but they can at least control the values of two consecutive bytes
   in the binary mouse reporting escape sequence.

   I went into more detail on that in the discussion at
   https://lore.kernel.org/all/20250221.0a947528d8f3@gnoack.org/

   It is not equally trivial to simulate arbitrary keystrokes as it
   was with TIOCSTI (commit 83efeeeb3d04 ("tty: Allow TIOCSTI to be
   disabled")), but the general mechanism is there, and together with
   the small number of existing legit use cases (see below), it would
   be better to revert back to requiring CAP_SYS_ADMIN for
   TIOCL_SELMOUSEREPORT, as it was already the case before
   commit 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without
   CAP_SYS_ADMIN").

3. TIOCL_SELMOUSEREPORT is only used by the mouse daemons (GPM or
   Consolation), and they are the only legit use case:

   To quote console_codes(4):

     The mouse tracking facility is intended to return
     xterm(1)-compatible mouse status reports.  Because the console
     driver has no way to know the device or type of the mouse, these
     reports are returned in the console input stream only when the
     virtual terminal driver receives a mouse update ioctl.  These
     ioctls must be generated by a mouse-aware user-mode application
     such as the gpm(8) daemon.

   Jared Finder has also confirmed in
   https://lore.kernel.org/all/491f3df9de6593df8e70dbe77614b026@finder.org/
   that Emacs does not call TIOCL_SELMOUSEREPORT directly, and it
   would be difficult to find good reasons for doing that, given that
   it would interfere with the reports that GPM is sending.

   More information on the interaction between GPM, terminals and the
   kernel with additional pointers is also available in this patch:
   https://lore.kernel.org/all/a773e48920aa104a65073671effbdee665c105fc.1603963593.git.tammo.block@gmail.com/

   For background on who else uses TIOCL_SELMOUSEREPORT: Debian Code
   search finds one page of results, the only two known callers are
   the two mouse daemons GPM and Consolation.  (GPM does not show up
   in the search results because it uses literal numbers to refer to
   TIOCLINUX-related enums.  I looked through GPM by hand instead.
   TIOCL_SELMOUSEREPORT is also not used from libgpm.)
   https://codesearch.debian.net/search?q=TIOCL_SELMOUSEREPORT

Cc: Jared Finder 
Cc: Jann Horn 
Cc: Hanno Böck 
Cc: Jiri Slaby 
Cc: Kees Cook 
Cc: stable 
Fixes: 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN")
Signed-off-by: Günther Noack 
Link: https://lore.kernel.org/r/20250411070144.3959-2-gnoack3000@gmail.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register

2025-04-10T12:44:43+00:00

[ Upstream commit e98ab45ec5182605d2e00114cba3bbf46b0ea27f ]

No need to overwrite the whole UARTMODIR register before waiting the
transmit engine complete, actually our target here is only to disable
CTS flow control to avoid the dirty data in TX FIFO may block the
transmit engine complete.
Also delete the following duplicate CTS disable configuration.

Fixes: d5a2e0834364 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete")
Cc: stable 
Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning

2025-04-10T12:44:43+00:00

commit 9f8fe348ac9544f6855f82565e754bf085d81f88 upstream.

Remove the unused variable 'sport' to avoid the kernel build warning.

Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/
Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: use port struct directly to simply code

2025-04-10T12:44:43+00:00

commit 3cc16ae096f164ae0c6b98416c25a01db5f3a529 upstream.

Most lpuart functions have the parameter struct uart_port *port, but
still use the &sport->port to get the uart_port instead of use it
directly, let's simply the code logic, directly use this struct instead
of covert it from struct sport.

Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman