From 1039bffd6ae9c75b42b7d148d6c1106134107b66 Mon Sep 17 00:00:00 2001 From: Xie Yuanbin Date: Tue, 28 Jul 2026 03:16:42 +0100 Subject: ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults 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 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) Reviewed-by: Linus Walleij Signed-off-by: Qi Xi Signed-off-by: Xie Yuanbin Signed-off-by: Russell King --- drivers/memory/Makefile | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 drivers/memory/Makefile (limited to 'drivers/memory/Makefile') diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile new file mode 100644 index 000000000..3ee883c87 --- /dev/null +++ b/drivers/memory/Makefile @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for memory devices +# + +obj-$(CONFIG_DDR) += jedec_ddr_data.o +ifeq ($(CONFIG_DDR),y) +obj-$(CONFIG_OF) += of_memory.o +endif +obj-$(CONFIG_ARM_PL172_MPMC) += pl172.o +obj-$(CONFIG_ATMEL_EBI) += atmel-ebi.o +obj-$(CONFIG_BRCMSTB_DPFE) += brcmstb_dpfe.o +obj-$(CONFIG_BRCMSTB_MEMC) += brcmstb_memc.o +obj-$(CONFIG_TI_AEMIF) += ti-aemif.o +obj-$(CONFIG_TI_EMIF) += emif.o +obj-$(CONFIG_OMAP_GPMC) += omap-gpmc.o +obj-$(CONFIG_FSL_CORENET_CF) += fsl-corenet-cf.o +obj-$(CONFIG_FSL_IFC) += fsl_ifc.o +obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o +obj-$(CONFIG_JZ4780_NEMC) += jz4780-nemc.o +obj-$(CONFIG_MTK_SMI) += mtk-smi.o +obj-$(CONFIG_DA8XX_DDRCTL) += da8xx-ddrctl.o +obj-$(CONFIG_PL353_SMC) += pl353-smc.o +obj-$(CONFIG_RENESAS_RPCIF) += renesas-rpc-if.o +obj-$(CONFIG_STM32_FMC2_EBI) += stm32-fmc2-ebi.o +obj-$(CONFIG_STM32_OMM) += stm32_omm.o + +obj-$(CONFIG_SAMSUNG_MC) += samsung/ +obj-$(CONFIG_TEGRA_MC) += tegra/ +obj-$(CONFIG_TI_EMIF_SRAM) += ti-emif-sram.o +obj-$(CONFIG_FPGA_DFL_EMIF) += dfl-emif.o + +ti-emif-sram-objs := ti-emif-pm.o ti-emif-sram-pm.o + +$(obj)/ti-emif-sram-pm.o: $(obj)/ti-emif-asm-offsets.h + +$(obj)/ti-emif-asm-offsets.h: $(obj)/emif-asm-offsets.s FORCE + $(call filechk,offsets,__TI_EMIF_ASM_OFFSETS_H__) + +targets += emif-asm-offsets.s +clean-files += ti-emif-asm-offsets.h -- cgit v1.3.1