From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- security/landlock/Kconfig | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 security/landlock/Kconfig (limited to 'security/landlock/Kconfig') diff --git a/security/landlock/Kconfig b/security/landlock/Kconfig new file mode 100644 index 000000000..3f1493402 --- /dev/null +++ b/security/landlock/Kconfig @@ -0,0 +1,37 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config SECURITY_LANDLOCK + bool "Landlock support" + depends on SECURITY + select SECURITY_NETWORK + select SECURITY_PATH + help + Landlock is a sandboxing mechanism that enables processes to restrict + themselves (and their future children) by gradually enforcing + tailored access control policies. A Landlock security policy is a + set of access rights (e.g. open a file in read-only, make a + directory, etc.) tied to a file hierarchy. Such policy can be + configured and enforced by any processes for themselves using the + dedicated system calls: landlock_create_ruleset(), + landlock_add_rule(), and landlock_restrict_self(). + + See Documentation/userspace-api/landlock.rst for further information. + + If you are unsure how to answer this question, answer N. Otherwise, + you should also prepend "landlock," to the content of CONFIG_LSM to + enable Landlock at boot time. + +config SECURITY_LANDLOCK_KUNIT_TEST + bool "KUnit tests for Landlock" if !KUNIT_ALL_TESTS + depends on KUNIT=y + depends on SECURITY_LANDLOCK + default KUNIT_ALL_TESTS + help + Build KUnit tests for Landlock. + + See the KUnit documentation in Documentation/dev-tools/kunit + + Run all KUnit tests for Landlock with: + ./tools/testing/kunit/kunit.py run --kunitconfig security/landlock + + If you are unsure how to answer this question, answer N. -- cgit v1.3.1