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/jffs2/ioctl.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 fs/jffs2/ioctl.c (limited to 'fs/jffs2/ioctl.c') diff --git a/fs/jffs2/ioctl.c b/fs/jffs2/ioctl.c new file mode 100644 index 000000000..859a598af --- /dev/null +++ b/fs/jffs2/ioctl.c @@ -0,0 +1,22 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2001-2007 Red Hat, Inc. + * Copyright © 2004-2010 David Woodhouse + * + * Created by David Woodhouse + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include +#include "nodelist.h" + +long jffs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + /* Later, this will provide for lsattr.jffs2 and chattr.jffs2, which + will include compression support etc. */ + return -ENOTTY; +} + -- cgit v1.3.1