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 --- Documentation/rust/index.rst | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/rust/index.rst (limited to 'Documentation/rust/index.rst') diff --git a/Documentation/rust/index.rst b/Documentation/rust/index.rst new file mode 100644 index 000000000..b78ed0efa --- /dev/null +++ b/Documentation/rust/index.rst @@ -0,0 +1,42 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Rust +==== + +Documentation related to Rust within the kernel. To start using Rust +in the kernel, please read the quick-start.rst guide. + + +Code documentation +------------------ + +Given a kernel configuration, the kernel may generate Rust code documentation, +i.e. HTML rendered by the ``rustdoc`` tool. + +.. only:: rustdoc and html + + This kernel documentation was built with `Rust code documentation + `_. + +.. only:: not rustdoc and html + + This kernel documentation was not built with Rust code documentation. + +A pregenerated version is provided at: + + https://rust.docs.kernel.org + +Please see the :ref:`Code documentation ` section for +more details. + +.. toctree:: + :maxdepth: 1 + + quick-start + general-information + coding-guidelines + arch-support + testing + +You can also find learning materials for Rust in its section in +:doc:`../process/kernel-docs`. -- cgit v1.3.1