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/dt-bindings/input/input.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 include/dt-bindings/input/input.h (limited to 'include/dt-bindings/input/input.h') diff --git a/include/dt-bindings/input/input.h b/include/dt-bindings/input/input.h new file mode 100644 index 000000000..bcf0ae100 --- /dev/null +++ b/include/dt-bindings/input/input.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * This header provides constants for most input bindings. + * + * Most input bindings include key code, matrix key code format. + * In most cases, key code and matrix key code format uses + * the standard values/macro defined in this header. + */ + +#ifndef _DT_BINDINGS_INPUT_INPUT_H +#define _DT_BINDINGS_INPUT_INPUT_H + +#include "linux-event-codes.h" + +#define MATRIX_KEY(row, col, code) \ + ((((row) & 0xFF) << 24) | (((col) & 0xFF) << 16) | ((code) & 0xFFFF)) + +#endif /* _DT_BINDINGS_INPUT_INPUT_H */ -- cgit v1.3.1