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, 49 insertions, 0 deletions

diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
new file mode 100644
index 000000000..5a950c7ab
--- /dev/null
+++ b/drivers/crypto/Makefile
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CRYPTO_DEV_ALLWINNER) += allwinner/
+obj-$(CONFIG_CRYPTO_DEV_ASPEED) += aspeed/
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_AES) += atmel-aes.o
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_SHA) += atmel-sha.o
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_TDES) += atmel-tdes.o
+# __init ordering requires atmel-i2c being before atmel-ecc and atmel-sha204a.
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_I2C) += atmel-i2c.o
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_ECC) += atmel-ecc.o
+obj-$(CONFIG_CRYPTO_DEV_ATMEL_SHA204A) += atmel-sha204a.o
+obj-$(CONFIG_CRYPTO_DEV_CCP) += ccp/
+obj-$(CONFIG_CRYPTO_DEV_CCREE) += ccree/
+obj-$(CONFIG_CRYPTO_DEV_CHELSIO) += chelsio/
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_COMMON) += caam/
+obj-$(CONFIG_CRYPTO_DEV_GEODE) += geode-aes.o
+obj-$(CONFIG_CRYPTO_DEV_HIFN_795X) += hifn_795x.o
+obj-$(CONFIG_CRYPTO_DEV_IMGTEC_HASH) += img-hash.o
+obj-$(CONFIG_CRYPTO_DEV_MARVELL) += marvell/
+obj-$(CONFIG_CRYPTO_DEV_MXS_DCP) += mxs-dcp.o
+obj-$(CONFIG_CRYPTO_DEV_NX) += nx/
+obj-$(CONFIG_CRYPTO_DEV_OMAP) += omap-crypto.o
+obj-$(CONFIG_CRYPTO_DEV_OMAP_AES) += omap-aes-driver.o
+omap-aes-driver-objs := omap-aes.o omap-aes-gcm.o
+obj-$(CONFIG_CRYPTO_DEV_OMAP_DES) += omap-des.o
+obj-$(CONFIG_CRYPTO_DEV_OMAP_SHAM) += omap-sham.o
+obj-$(CONFIG_CRYPTO_DEV_PADLOCK_AES) += padlock-aes.o
+obj-$(CONFIG_CRYPTO_DEV_PADLOCK_SHA) += padlock-sha.o
+obj-$(CONFIG_CRYPTO_DEV_PPC4XX) += amcc/
+obj-$(CONFIG_CRYPTO_DEV_QCE) += qce/
+obj-$(CONFIG_CRYPTO_DEV_QCOM_RNG) += qcom-rng.o
+obj-$(CONFIG_CRYPTO_DEV_ROCKCHIP) += rockchip/
+obj-$(CONFIG_CRYPTO_DEV_S5P) += s5p-sss.o
+obj-$(CONFIG_CRYPTO_DEV_SA2UL) += sa2ul.o
+obj-$(CONFIG_CRYPTO_DEV_SAHARA) += sahara.o
+obj-$(CONFIG_CRYPTO_DEV_SL3516) += gemini/
+obj-y += stm32/
+obj-$(CONFIG_CRYPTO_DEV_TALITOS) += talitos.o
+obj-$(CONFIG_CRYPTO_DEV_TEGRA) += tegra/
+obj-$(CONFIG_CRYPTO_DEV_VIRTIO) += virtio/
+obj-$(CONFIG_CRYPTO_DEV_BCM_SPU) += bcm/
+obj-y += inside-secure/
+obj-$(CONFIG_CRYPTO_DEV_ARTPEC6) += axis/
+obj-y += xilinx/
+obj-y += hisilicon/
+obj-$(CONFIG_CRYPTO_DEV_AMLOGIC_GXL) += amlogic/
+obj-y += intel/
+obj-y += starfive/
+obj-y += cavium/
+obj-y += ti/