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 --- fs/affs/Kconfig | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 fs/affs/Kconfig (limited to 'fs/affs/Kconfig') diff --git a/fs/affs/Kconfig b/fs/affs/Kconfig new file mode 100644 index 000000000..1ae432d26 --- /dev/null +++ b/fs/affs/Kconfig @@ -0,0 +1,24 @@ +# SPDX-License-Identifier: GPL-2.0-only +config AFFS_FS + tristate "Amiga FFS file system support" + depends on BLOCK + select BUFFER_HEAD + select LEGACY_DIRECT_IO + help + The Fast File System (FFS) is the common file system used on hard + disks by Amiga(tm) systems since AmigaOS Version 1.3 (34.20). Say Y + if you want to be able to read and write files from and to an Amiga + FFS partition on your hard drive. Amiga floppies however cannot be + read with this driver due to an incompatibility of the floppy + controller used in an Amiga and the standard floppy controller in + PCs and workstations. Read + and . + + With this driver you can also mount disk files used by Bernd + Schmidt's Un*X Amiga Emulator + (). + If you want to do this, you will also need to say Y or M to "Loop + device support", above. + + To compile this file system support as a module, choose M here: the + module will be called affs. If unsure, say N. -- cgit v1.3.1