ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faultsgrafted

When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set,
a user fault may trigger show_pte() without any lock.
If another thread in the same process concurrently calls munmap(),
the page table pages may be freed while show_pte() is still traversing
them, causing a use-after-free in show_pte().

If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table
of PMD are freed when show_pte() is running.

Acquire mmap_write_lock() around show_pte() for user faults to fix the
contention.

For user faults, additionally restrict that show_pte() is called only
when the addr is a user-space address (addr < TASK_SIZE). This is because
the lock of tsk->mm only protects the virtual memory of user address space,
furthermore, dumping the page tables of a kernel-space address for user
faults is unnecessary and may have security implications.

Keep everything unchanged for kernel faults, because the kernel is
already in the "oops" state, acquiring a lock may risk a deadlock.

Co-developed-by: Qi Xi <xiqi2@huawei.com>

Fixes: 6d021b724481 ("ARM: dump pgd, pmd and pte states on unhandled data abort faults")
Link: https://lore.kernel.org/20260716014022.2823-1-xieyuanbin1@huawei.com
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 43 insertions, 0 deletions

diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
new file mode 100644
index 000000000..9976f596a
--- /dev/null
+++ b/drivers/input/joystick/Makefile
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the input core drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_JOYSTICK_A3D)		+= a3d.o
+obj-$(CONFIG_JOYSTICK_ADC)		+= adc-joystick.o
+obj-$(CONFIG_JOYSTICK_ADI)		+= adi.o
+obj-$(CONFIG_JOYSTICK_AMIGA)		+= amijoy.o
+obj-$(CONFIG_JOYSTICK_AS5011)		+= as5011.o
+obj-$(CONFIG_JOYSTICK_ANALOG)		+= analog.o
+obj-$(CONFIG_JOYSTICK_COBRA)		+= cobra.o
+obj-$(CONFIG_JOYSTICK_DB9)		+= db9.o
+obj-$(CONFIG_JOYSTICK_FSIA6B)		+= fsia6b.o
+obj-$(CONFIG_JOYSTICK_GAMECON)		+= gamecon.o
+obj-$(CONFIG_JOYSTICK_GF2K)		+= gf2k.o
+obj-$(CONFIG_JOYSTICK_GRIP)		+= grip.o
+obj-$(CONFIG_JOYSTICK_GRIP_MP)		+= grip_mp.o
+obj-$(CONFIG_JOYSTICK_GUILLEMOT)	+= guillemot.o
+obj-$(CONFIG_JOYSTICK_IFORCE)		+= iforce/
+obj-$(CONFIG_JOYSTICK_INTERACT)		+= interact.o
+obj-$(CONFIG_JOYSTICK_JOYDUMP)		+= joydump.o
+obj-$(CONFIG_JOYSTICK_MAGELLAN)		+= magellan.o
+obj-$(CONFIG_JOYSTICK_MAPLE)		+= maplecontrol.o
+obj-$(CONFIG_JOYSTICK_N64)		+= n64joy.o
+obj-$(CONFIG_JOYSTICK_PSXPAD_SPI)	+= psxpad-spi.o
+obj-$(CONFIG_JOYSTICK_PXRC)		+= pxrc.o
+obj-$(CONFIG_JOYSTICK_QWIIC)		+= qwiic-joystick.o
+obj-$(CONFIG_JOYSTICK_SEESAW)		+= adafruit-seesaw.o
+obj-$(CONFIG_JOYSTICK_SENSEHAT)	+= sensehat-joystick.o
+obj-$(CONFIG_JOYSTICK_SIDEWINDER)	+= sidewinder.o
+obj-$(CONFIG_JOYSTICK_SPACEBALL)	+= spaceball.o
+obj-$(CONFIG_JOYSTICK_SPACEORB)		+= spaceorb.o
+obj-$(CONFIG_JOYSTICK_STINGER)		+= stinger.o
+obj-$(CONFIG_JOYSTICK_TMDC)		+= tmdc.o
+obj-$(CONFIG_JOYSTICK_TURBOGRAFX)	+= turbografx.o
+obj-$(CONFIG_JOYSTICK_TWIDJOY)		+= twidjoy.o
+obj-$(CONFIG_JOYSTICK_WARRIOR)		+= warrior.o
+obj-$(CONFIG_JOYSTICK_WALKERA0701)	+= walkera0701.o
+obj-$(CONFIG_JOYSTICK_XPAD)		+= xpad.o
+obj-$(CONFIG_JOYSTICK_ZHENHUA)		+= zhenhua.o