linux-stable.git/drivers/tty, branch v6.4.8

tty: n_gsm: fix UAF in gsm_cleanup_mux

2023-08-03T08:26:05+00:00

commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239 upstream.

In gsm_cleanup_mux() the 'gsm->dlci' pointer was not cleaned properly,
leaving it a dangling pointer after gsm_dlci_release.
This leads to use-after-free where 'gsm->dlci[0]' are freed and accessed
by the subsequent gsm_cleanup_mux().

Such is the case in the following call trace:

 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 gsm_cleanup_mux+0x76a/0x850 drivers/tty/n_gsm.c:2397
 gsm_config drivers/tty/n_gsm.c:2653 [inline]
 gsmld_ioctl+0xaae/0x15b0 drivers/tty/n_gsm.c:2986
 tty_ioctl+0x8ff/0xc50 drivers/tty/tty_io.c:2816
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
 

Allocated by task 3501:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 kmem_cache_alloc_trace+0x143/0x290 mm/slub.c:3247
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 gsm_dlci_alloc+0x53/0x3a0 drivers/tty/n_gsm.c:1932
 gsm_activate_mux+0x1c/0x330 drivers/tty/n_gsm.c:2438
 gsm_config drivers/tty/n_gsm.c:2677 [inline]
 gsmld_ioctl+0xd46/0x15b0 drivers/tty/n_gsm.c:2986
 tty_ioctl+0x8ff/0xc50 drivers/tty/tty_io.c:2816
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 3501:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0xf1/0x270 mm/slub.c:4559
 dlci_put drivers/tty/n_gsm.c:1988 [inline]
 gsm_dlci_release drivers/tty/n_gsm.c:2021 [inline]
 gsm_cleanup_mux+0x574/0x850 drivers/tty/n_gsm.c:2415
 gsm_config drivers/tty/n_gsm.c:2653 [inline]
 gsmld_ioctl+0xaae/0x15b0 drivers/tty/n_gsm.c:2986
 tty_ioctl+0x8ff/0xc50 drivers/tty/tty_io.c:2816
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Fixes: aa371e96f05d ("tty: n_gsm: fix restart handling via CLD command")
Signed-off-by: Chaoyuan Peng 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

TIOCSTI: always enable for CAP_SYS_ADMIN

2023-08-03T08:26:03+00:00

commit 690c8b804ad2eafbd35da5d3c95ad325ca7d5061 upstream.

83efeeeb3d04 ("tty: Allow TIOCSTI to be disabled") broke BRLTTY's
ability to simulate keypresses on the console, thus effectively breaking
braille keyboards of blind users.

This restores the TIOCSTI feature for CAP_SYS_ADMIN processes, which
BRLTTY is, thus fixing braille keyboards without re-opening the security
issue.

Signed-off-by: Samuel Thibault 
Acked-by: Kees Cook 
Fixes: 83efeeeb3d04 ("tty: Allow TIOCSTI to be disabled")
Cc: stable@vger.kernel.org
Reported-by: Nicolas Pitre 
Link: https://lore.kernel.org/r/20230710002645.v565c7xq5iddruse@begin
Acked-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

serial: sifive: Fix sifive_serial_console_setup() section

2023-08-03T08:26:02+00:00

commit 9b8fef6345d5487137d4193bb0a0eae2203c284e upstream.

This function is called indirectly from the platform driver probe
function. Even if the driver is built in, it may be probed after
free_initmem() due to deferral or unbinding/binding via sysfs.
Thus the function cannot be marked as __init.

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Cc: stable 
Signed-off-by: Samuel Holland 
Link: https://lore.kernel.org/r/20230624060159.3401369-1-samuel.holland@sifive.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Preserve original value of DLF register

2023-08-03T08:26:02+00:00

commit 748c5ea8b8796ae8ee80b8d3a3d940570b588d59 upstream.

Preserve the original value of the Divisor Latch Fraction (DLF) register.
When the DLF register is modified without preservation, it can disrupt
the baudrate settings established by firmware or bootloader, leading to
data corruption and the generation of unreadable or distorted characters.

Fixes: 701c5e73b296 ("serial: 8250_dw: add fractional divisor support")
Cc: stable 
Signed-off-by: Ruihong Luo 
Link: https://lore.kernel.org/stable/20230713004235.35904-1-colorsu1922%40gmail.com
Reviewed-by: Ilpo Järvinen 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230713004235.35904-1-colorsu1922@gmail.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: sh-sci: Fix sleeping in atomic context

2023-08-03T08:26:02+00:00

commit 57c984f6fe20ebb9306d6e8c09b4f67fe63298c6 upstream.

Fix sleeping in atomic context warning as reported by the Smatch static
checker tool by replacing disable_irq->disable_irq_nosync.

Reported by: Dan Carpenter 

Fixes: 8749061be196 ("tty: serial: sh-sci: Add RZ/G2L SCIFA DMA tx support")
Cc: stable@kernel.org
Signed-off-by: Biju Das 
Reviewed-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20230704154818.406913-1-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman

serial: qcom-geni: drop bogus runtime pm state update

2023-08-03T08:26:02+00:00

commit 4dd8752a14ca0303fbdf0a6c68ff65f0a50bd2fa upstream.

The runtime PM state should not be changed by drivers that do not
implement runtime PM even if it happens to work around a bug in PM core.

With the wake irq arming now fixed, drop the bogus runtime PM state
update which left the device in active state (and could potentially
prevent a parent device from suspending).

Fixes: f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup")
Cc: 5.6+  # 5.6+
Signed-off-by: Johan Hovold 
Reviewed-by: Tony Lindgren 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

Revert "8250: add support for ASIX devices with a FIFO bug"

2023-07-23T11:54:08+00:00

commit a82d62f708545d22859584e0e0620da8e3759bbc upstream.

This reverts commit eb26dfe8aa7eeb5a5aa0b7574550125f8aa4c3b3.

Commit eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO
bug") merged on Jul 13, 2012 adds a quirk for PCI_VENDOR_ID_ASIX
(0x9710). But that ID is the same as PCI_VENDOR_ID_NETMOS defined in
1f8b061050c7 ("[PATCH] Netmos parallel/serial/combo support") merged
on Mar 28, 2005. In pci_serial_quirks array, the NetMos entry always
takes precedence over the ASIX entry even since it was initially
merged, code in that commit is always unreachable.

In my tests, adding the FIFO workaround to pci_netmos_init() makes no
difference, and the vendor driver also does not have such workaround.
Given that the code was never used for over a decade, it's safe to
revert it.

Also, the real PCI_VENDOR_ID_ASIX should be 0x125b, which is used on
their newer AX99100 PCIe serial controllers released on 2016. The FIFO
workaround should not be intended for these newer controllers, and it
was never implemented in vendor driver.

Fixes: eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug")
Cc: stable 
Signed-off-by: Jiaqing Zhao 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230619155743.827859-1-jiaqing.zhao@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

tty: fix hang on tty device with no_room set

2023-07-23T11:54:06+00:00

commit 4903fde8047a28299d1fc79c1a0dcc255e928f12 upstream.

It is possible to hang pty devices in this case, the reader was
blocking at epoll on master side, the writer was sleeping at
wait_woken inside n_tty_write on slave side, and the write buffer
on tty_port was full, we found that the reader and writer would
never be woken again and blocked forever.

The problem was caused by a race between reader and kworker:
n_tty_read(reader):  n_tty_receive_buf_common(kworker):
copy_from_read_buf()|
                    |room = N_TTY_BUF_SIZE - (ldata->read_head - tail)
                    |room <= 0
n_tty_kick_worker() |
                    |ldata->no_room = true

After writing to slave device, writer wakes up kworker to flush
data on tty_port to reader, and the kworker finds that reader
has no room to store data so room <= 0 is met. At this moment,
reader consumes all the data on reader buffer and calls
n_tty_kick_worker to check ldata->no_room which is false and
reader quits reading. Then kworker sets ldata->no_room=true
and quits too.

If write buffer is not full, writer will wake kworker to flush data
again after following writes, but if write buffer is full and writer
goes to sleep, kworker will never be woken again and tty device is
blocked.

This problem can be solved with a check for read buffer size inside
n_tty_receive_buf_common, if read buffer is empty and ldata->no_room
is true, a call to n_tty_kick_worker is necessary to keep flushing
data to reader.

Cc: 
Fixes: 42458f41d08f ("n_tty: Ensure reader restarts worker for next reader")
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Hui Li 
Message-ID: <1680749090-14106-1-git-send-email-caelli@tencent.com>
Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: fix rs485 rx after tx

2023-07-23T11:54:05+00:00

commit 639949a7031e04c59ec91614eceb9543e9120f43 upstream.

Since commit 79d0224f6bf2 ("tty: serial: imx: Handle RS485 DE signal
active high") RS485 reception no longer works after a transmission.

The following scenario shows the problem:
	1) Open a port in RS485 mode
	2) Receive data from remote (OK)
	3) Transmit data to remote (OK)
	4) Receive data from remote (Nothing received)

In RS485 mode, imx_uart_start_tx() calls imx_uart_stop_rx() and, when the
transmission is complete, imx_uart_stop_tx() calls imx_uart_start_rx().

Since the above commit imx_uart_stop_rx() now sets the loopback bit but
imx_uart_start_rx() does not clear it causing the hardware to remain in
loopback mode and not receive external data.

Fix this by moving the existing loopback disable code to a helper function
and calling it from imx_uart_start_rx() too.

Fixes: 79d0224f6bf2 ("tty: serial: imx: Handle RS485 DE signal active high")
Cc: stable@vger.kernel.org
Signed-off-by: Martin Fuzzey 
Reviewed-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20230616104838.2729694-1-martin.fuzzey@flowbird.group
Signed-off-by: Greg Kroah-Hartman

tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk

2023-07-23T11:54:05+00:00

commit 832e231cff476102e8204a9e7bddfe5c6154a375 upstream.

When the best clk is searched, we iterate over all possible clk.

If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.

Cc:  # v3.3+
Reviewed-by: Krzysztof Kozlowski 
Reviewed-by: Andi Shyti 
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Jiri Slaby 
Message-ID: 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman