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 --- include/sound/sof/pm.h | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 include/sound/sof/pm.h (limited to 'include/sound/sof/pm.h') diff --git a/include/sound/sof/pm.h b/include/sound/sof/pm.h new file mode 100644 index 000000000..df55bfe58 --- /dev/null +++ b/include/sound/sof/pm.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */ +/* + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * Copyright(c) 2018 Intel Corporation + */ + +#ifndef __INCLUDE_SOUND_SOF_PM_H__ +#define __INCLUDE_SOUND_SOF_PM_H__ + +#include + +/* + * PM + */ + +/* PM context element */ +struct sof_ipc_pm_ctx_elem { + struct sof_ipc_hdr hdr; + uint32_t type; + uint32_t size; + uint64_t addr; +} __packed; + +/* + * PM context - SOF_IPC_PM_CTX_SAVE, SOF_IPC_PM_CTX_RESTORE, + * SOF_IPC_PM_CTX_SIZE + */ +struct sof_ipc_pm_ctx { + struct sof_ipc_cmd_hdr hdr; + struct sof_ipc_host_buffer buffer; + uint32_t num_elems; + uint32_t size; + + /* reserved for future use */ + uint32_t reserved[8]; + + struct sof_ipc_pm_ctx_elem elems[]; +} __packed; + +/* enable or disable cores - SOF_IPC_PM_CORE_ENABLE */ +struct sof_ipc_pm_core_config { + struct sof_ipc_cmd_hdr hdr; + uint32_t enable_mask; +} __packed; + +struct sof_ipc_pm_gate { + struct sof_ipc_cmd_hdr hdr; + uint32_t flags; /* platform specific */ + + /* reserved for future use */ + uint32_t reserved[5]; +} __packed; + +#endif -- cgit v1.3.1