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 --- rust/zerocopy/rustdoc/style.css | 57 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 rust/zerocopy/rustdoc/style.css (limited to 'rust/zerocopy/rustdoc') diff --git a/rust/zerocopy/rustdoc/style.css b/rust/zerocopy/rustdoc/style.css new file mode 100644 index 000000000..414348964 --- /dev/null +++ b/rust/zerocopy/rustdoc/style.css @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: (BSD-2-Clause OR Apache-2.0) OR MIT */ + +/* +Copyright 2026 The Fuchsia Authors + +Licensed under a BSD-style license , Apache License, Version 2.0 +, or the MIT +license , at your option. +This file may not be copied, modified, or distributed except according to +those terms. +*/ + +.codegen-tabs { + display: grid; + grid-template-columns: repeat(var(--arity), minmax(200px, 1fr)); + grid-template-rows: auto 1fr; + column-gap: 1rem; +} + +.codegen-tabs:not(:has(> details[open]))::after { + grid-column: 1/-1; + content: 'Click one of the above headers to expand its contents.'; + font-style: italic; + font-size: small; + text-align: center; +} + +.codegen-tabs details { + display: grid; + grid-column: 1 / -1; + grid-row: 1 / span 2; + grid-template-columns: subgrid; + grid-template-rows: subgrid; +} + +.codegen-tabs summary { + display: grid; + grid-column: var(--n) / span 1; + grid-row: 1; + z-index: 1; + border-bottom: 2px solid var(--headings-border-bottom-color); + cursor: pointer; +} + +.codegen-tabs details[open] > summary { + background-color: var(--code-block-background-color); + border-bottom-color: var(--target-border-color); +} + +.codegen-tabs details::details-content { + grid-column: 1 / -1; + grid-row: 2; +} + +.codegen-tabs details:not([open])::details-content { + display: none; +} -- cgit v1.3.1