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/netevent.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 include/net/netevent.h (limited to 'include/net/netevent.h') diff --git a/include/net/netevent.h b/include/net/netevent.h new file mode 100644 index 000000000..1be3757a8 --- /dev/null +++ b/include/net/netevent.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_EVENT_H +#define _NET_EVENT_H + +/* + * Generic netevent notifiers + * + * Authors: + * Tom Tucker + * Steve Wise + * + * Changes: + */ + +struct dst_entry; +struct neighbour; +struct notifier_block ; + +struct netevent_redirect { + struct dst_entry *old; + struct dst_entry *new; + struct neighbour *neigh; + const void *daddr; +}; + +enum netevent_notif_type { + NETEVENT_NEIGH_UPDATE = 1, /* arg is struct neighbour ptr */ + NETEVENT_REDIRECT, /* arg is struct netevent_redirect ptr */ + NETEVENT_DELAY_PROBE_TIME_UPDATE, /* arg is struct neigh_parms ptr */ + NETEVENT_IPV4_MPATH_HASH_UPDATE, /* arg is struct net ptr */ + NETEVENT_IPV6_MPATH_HASH_UPDATE, /* arg is struct net ptr */ + NETEVENT_IPV4_FWD_UPDATE_PRIORITY_UPDATE, /* arg is struct net ptr */ +}; + +int register_netevent_notifier(struct notifier_block *nb); +int unregister_netevent_notifier(struct notifier_block *nb); +int call_netevent_notifiers(unsigned long val, void *v); + +#endif -- cgit v1.3.1