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 <ryotkkr98@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness <john.ogness@linutronix.de>
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 <gregkh@linuxfoundation.org>
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 <stable@kernel.org>
Fixes: 0efe72963409 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <jared@finder.org>
Cc: Jann Horn <jannh@google.com>
Cc: Hanno Böck <hanno@hboeck.de>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: stable <stable@kernel.org>
Fixes: 2f83e38a095f ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN")
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250411070144.3959-2-gnoack3000@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 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 <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b6a8f6ab2c53e5ea3c7f2a3978db378a89bb7595 ]
Use u32 and u8 rather than unsigned long or unsigned char for register
variables for clarity and consistency.
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d97aa066678bd1e2951ee93db9690835dfe57ab6 ]
tty_write_room() returns an "unsigned int". So in case some insane
driver (like my tty test driver) returns (legitimate) UINT_MAX from its
tty_operations::write_room(), n_tty is confused on several places.
For example, in process_output_block(), the result of tty_write_room()
is stored into (signed) "int". So this UINT_MAX suddenly becomes -1. And
that is extended to ssize_t and returned from process_output_block().
This causes a write() to such a node to receive -EPERM (which is -1).
Fix that by using proper "unsigned int" and proper "== 0" test. And
return 0 constant directly in that "if", so that it is immediately clear
what is returned ("space" equals to 0 at that point).
Similarly for process_output() and __process_echoes().
Note this does not fix any in-tree driver as of now.
If you want "Fixes: something", it would be commit 03b3b1a2405c ("tty:
make tty_operations::write_room return uint"). I intentionally do not
mark this patch by a real tag below.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a26503092c75abba70a0be2aa01145ecf90c2a22 upstream.
When flushing transmit side DMA, it is the transmit channel that should
be terminated, not the receive channel.
Fixes: 9e512eaaf8f40 ("serial: 8250: Fix fifo underflow on flush")
Cc: stable <stable@kernel.org>
Reported-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2790ce23951f0c497810c44ad60a126a59c8d84c upstream.
If stm32_usart_start_tx is called with an empty xmit buffer, RTS GPIO
could be deasserted prematurely, as bytes in TX FIFO are still
transmitting.
So this patch remove rts disable when xmit buffer is empty.
Fixes: d7c76716169d ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode")
Cc: stable <stable@kernel.org>
Signed-off-by: Cheick Traore <cheick.traore@foss.st.com>
Link: https://lore.kernel.org/r/20250320152540.709091-1-cheick.traore@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>