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/cls_cgroup.h | 88 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 include/net/cls_cgroup.h (limited to 'include/net/cls_cgroup.h') diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h new file mode 100644 index 000000000..668aeee9b --- /dev/null +++ b/include/net/cls_cgroup.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * cls_cgroup.h Control Group Classifier + * + * Authors: Thomas Graf + */ + +#ifndef _NET_CLS_CGROUP_H +#define _NET_CLS_CGROUP_H + +#include +#include +#include +#include +#include + +#ifdef CONFIG_CGROUP_NET_CLASSID +struct cgroup_cls_state { + struct cgroup_subsys_state css; + u32 classid; +}; + +struct cgroup_cls_state *task_cls_state(struct task_struct *p); + +static inline u32 task_cls_classid(struct task_struct *p) +{ + u32 classid; + + if (in_interrupt()) + return 0; + + rcu_read_lock(); + classid = container_of(task_css(p, net_cls_cgrp_id), + struct cgroup_cls_state, css)->classid; + rcu_read_unlock(); + + return classid; +} + +static inline void sock_update_classid(struct sock_cgroup_data *skcd) +{ + u32 classid; + + classid = task_cls_classid(current); + sock_cgroup_set_classid(skcd, classid); +} + +static inline u32 __task_get_classid(struct task_struct *task) +{ + return task_cls_state(task)->classid; +} + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + u32 classid = __task_get_classid(current); + + /* Due to the nature of the classifier it is required to ignore all + * packets originating from softirq context as accessing `current' + * would lead to false results. + * + * This test assumes that all callers of dev_queue_xmit() explicitly + * disable bh. Knowing this, it is possible to detect softirq based + * calls by looking at the number of nested bh disable calls because + * softirqs always disables bh. + */ + if (softirq_count()) { + struct sock *sk = skb_to_full_sk(skb); + + /* If there is an sock_cgroup_classid we'll use that. */ + if (!sk || !sk_fullsock(sk)) + return 0; + + classid = sock_cgroup_classid(&sk->sk_cgrp_data); + } + + return classid; +} +#else /* !CONFIG_CGROUP_NET_CLASSID */ +static inline void sock_update_classid(struct sock_cgroup_data *skcd) +{ +} + +static inline u32 task_get_classid(const struct sk_buff *skb) +{ + return 0; +} +#endif /* CONFIG_CGROUP_NET_CLASSID */ +#endif /* _NET_CLS_CGROUP_H */ -- cgit v1.3.1