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 --- include/net/mip6.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 include/net/mip6.h (limited to 'include/net/mip6.h') diff --git a/include/net/mip6.h b/include/net/mip6.h new file mode 100644 index 000000000..67cd7e508 --- /dev/null +++ b/include/net/mip6.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C)2003-2006 Helsinki University of Technology + * Copyright (C)2003-2006 USAGI/WIDE Project + */ +/* + * Authors: + * Noriaki TAKAMIYA @USAGI + * Masahide NAKAMURA @USAGI + * YOSHIFUJI Hideaki @USAGI + */ +#ifndef _NET_MIP6_H +#define _NET_MIP6_H + +#include +#include + +/* + * Mobility Header + */ +struct ip6_mh { + __u8 ip6mh_proto; + __u8 ip6mh_hdrlen; + __u8 ip6mh_type; + __u8 ip6mh_reserved; + __u16 ip6mh_cksum; + /* Followed by type specific messages */ + __u8 data[]; +} __packed; + +#define IP6_MH_TYPE_BRR 0 /* Binding Refresh Request */ +#define IP6_MH_TYPE_HOTI 1 /* HOTI Message */ +#define IP6_MH_TYPE_COTI 2 /* COTI Message */ +#define IP6_MH_TYPE_HOT 3 /* HOT Message */ +#define IP6_MH_TYPE_COT 4 /* COT Message */ +#define IP6_MH_TYPE_BU 5 /* Binding Update */ +#define IP6_MH_TYPE_BACK 6 /* Binding ACK */ +#define IP6_MH_TYPE_BERROR 7 /* Binding Error */ +#define IP6_MH_TYPE_MAX IP6_MH_TYPE_BERROR + +#endif -- cgit v1.3.1