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 --- arch/powerpc/sysdev/Makefile | 50 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 arch/powerpc/sysdev/Makefile (limited to 'arch/powerpc/sysdev/Makefile') diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile new file mode 100644 index 000000000..0834a9a12 --- /dev/null +++ b/arch/powerpc/sysdev/Makefile @@ -0,0 +1,50 @@ +# SPDX-License-Identifier: GPL-2.0 + +mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o +obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) +obj-$(CONFIG_MPIC_TIMER) += mpic_timer.o +obj-$(CONFIG_FSL_MPIC_TIMER_WAKEUP) += fsl_mpic_timer_wakeup.o +mpic-msgr-obj-$(CONFIG_MPIC_MSGR) += mpic_msgr.o +obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y) $(mpic-msgr-obj-y) +obj-$(CONFIG_PPC_EPAPR_HV_PIC) += ehv_pic.o +fsl-msi-obj-$(CONFIG_PCI_MSI) += fsl_msi.o +obj-$(CONFIG_PPC_MSI_BITMAP) += msi_bitmap.o + +obj-$(CONFIG_PPC_MPC106) += grackle.o +obj-$(CONFIG_PPC_DCR_NATIVE) += dcr-low.o +obj-$(CONFIG_U3_DART) += dart_iommu.o +obj-$(CONFIG_MMIO_NVRAM) += mmio_nvram.o +obj-$(CONFIG_FSL_SOC) += fsl_soc.o fsl_mpic_err.o +obj-$(CONFIG_FSL_PCI) += fsl_pci.o $(fsl-msi-obj-y) +obj-$(CONFIG_FSL_PMC) += fsl_pmc.o +obj-$(CONFIG_FSL_CORENET_RCPM) += fsl_rcpm.o +obj-$(CONFIG_FSL_LBC) += fsl_lbc.o +obj-$(CONFIG_FSL_GTM) += fsl_gtm.o +obj-$(CONFIG_FSL_RIO) += fsl_rio.o fsl_rmu.o +obj-$(CONFIG_TSI108_BRIDGE) += tsi108_pci.o tsi108_dev.o +obj-$(CONFIG_RTC_DRV_CMOS) += rtc_cmos_setup.o + +obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o +obj-$(CONFIG_PPC_I8259) += i8259.o +obj-$(CONFIG_IPIC) += ipic.o +obj-$(CONFIG_OF_RTC) += of_rtc.o + +obj-$(CONFIG_CPM) += cpm_common.o +obj-$(CONFIG_CPM2) += cpm2.o cpm2_pic.o cpm_gpio.o +obj-$(CONFIG_8xx_GPIO) += cpm_gpio.o +obj-$(CONFIG_QUICC_ENGINE) += cpm_common.o +obj-$(CONFIG_PPC_DCR) += dcr.o + +obj-$(CONFIG_PPC_MPC512x) += mpc5xxx_clocks.o +obj-$(CONFIG_PPC_MPC52xx) += mpc5xxx_clocks.o + +ifdef CONFIG_SUSPEND +obj-$(CONFIG_PPC_BOOK3S_32) += 6xx-suspend.o +endif + +obj-$(CONFIG_PPC_EARLY_DEBUG_MEMCONS) += udbg_memcons.o + +obj-$(CONFIG_PPC_XICS) += xics/ +obj-$(CONFIG_PPC_XIVE) += xive/ + +obj-$(CONFIG_GE_FPGA) += ge/ -- cgit v1.3.1