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 --- net/dsa/netlink.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 net/dsa/netlink.c (limited to 'net/dsa/netlink.c') diff --git a/net/dsa/netlink.c b/net/dsa/netlink.c new file mode 100644 index 000000000..1332e5634 --- /dev/null +++ b/net/dsa/netlink.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright 2022 NXP + */ +#include +#include + +#include "netlink.h" +#include "user.h" + +static const struct nla_policy dsa_policy[IFLA_DSA_MAX + 1] = { + [IFLA_DSA_CONDUIT] = { .type = NLA_U32 }, +}; + +static int dsa_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + int err; + + if (!data) + return 0; + + if (data[IFLA_DSA_CONDUIT]) { + u32 ifindex = nla_get_u32(data[IFLA_DSA_CONDUIT]); + struct net_device *conduit; + + conduit = __dev_get_by_index(dev_net(dev), ifindex); + if (!conduit) + return -EINVAL; + + err = dsa_user_change_conduit(dev, conduit, extack); + if (err) + return err; + } + + return 0; +} + +static size_t dsa_get_size(const struct net_device *dev) +{ + return nla_total_size(sizeof(u32)) + /* IFLA_DSA_CONDUIT */ + 0; +} + +static int dsa_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct net_device *conduit = dsa_user_to_conduit(dev); + + if (nla_put_u32(skb, IFLA_DSA_CONDUIT, conduit->ifindex)) + return -EMSGSIZE; + + return 0; +} + +struct rtnl_link_ops dsa_link_ops __read_mostly = { + .kind = "dsa", + .priv_size = sizeof(struct dsa_port), + .maxtype = IFLA_DSA_MAX, + .policy = dsa_policy, + .changelink = dsa_changelink, + .get_size = dsa_get_size, + .fill_info = dsa_fill_info, + .netns_refund = true, +}; -- cgit v1.3.1