linux-stable/include/net/mrp.h
Schspa Shi ab0377803d mrp: introduce active flags to prevent UAF when applicant uninit
The caller of del_timer_sync must prevent restarting of the timer, If
we have no this synchronization, there is a small probability that the
cancellation will not be successful.

And syzbot report the fellowing crash:
==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:929 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0x18/0xa4 kernel/time/timer.c:605
Write at addr f9ff000024df6058 by task syz-fuzzer/2256
Pointer tag: [f9], memory tag: [fe]

CPU: 1 PID: 2256 Comm: syz-fuzzer Not tainted 6.1.0-rc5-syzkaller-00008-
ge01d50cbd6ee #0
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace.part.0+0xe0/0xf0 arch/arm64/kernel/stacktrace.c:156
 dump_backtrace arch/arm64/kernel/stacktrace.c:162 [inline]
 show_stack+0x18/0x40 arch/arm64/kernel/stacktrace.c:163
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x68/0x84 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x1a8/0x4a0 mm/kasan/report.c:395
 kasan_report+0x94/0xb4 mm/kasan/report.c:495
 __do_kernel_fault+0x164/0x1e0 arch/arm64/mm/fault.c:320
 do_bad_area arch/arm64/mm/fault.c:473 [inline]
 do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:749
 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:825
 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:367
 el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:427
 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576
 hlist_add_head include/linux/list.h:929 [inline]
 enqueue_timer+0x18/0xa4 kernel/time/timer.c:605
 mod_timer+0x14/0x20 kernel/time/timer.c:1161
 mrp_periodic_timer_arm net/802/mrp.c:614 [inline]
 mrp_periodic_timer+0xa0/0xc0 net/802/mrp.c:627
 call_timer_fn.constprop.0+0x24/0x80 kernel/time/timer.c:1474
 expire_timers+0x98/0xc4 kernel/time/timer.c:1519

To fix it, we can introduce a new active flags to make sure the timer will
not restart.

Reported-by: syzbot+6fd64001c20aa99e34a4@syzkaller.appspotmail.com

Signed-off-by: Schspa Shi <schspa@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-18 12:14:55 +00:00

148 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_MRP_H
#define _NET_MRP_H
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#define MRP_END_MARK 0x0
struct mrp_pdu_hdr {
u8 version;
};
struct mrp_msg_hdr {
u8 attrtype;
u8 attrlen;
};
struct mrp_vecattr_hdr {
__be16 lenflags;
unsigned char firstattrvalue[];
#define MRP_VECATTR_HDR_LEN_MASK cpu_to_be16(0x1FFF)
#define MRP_VECATTR_HDR_FLAG_LA cpu_to_be16(0x2000)
};
enum mrp_vecattr_event {
MRP_VECATTR_EVENT_NEW,
MRP_VECATTR_EVENT_JOIN_IN,
MRP_VECATTR_EVENT_IN,
MRP_VECATTR_EVENT_JOIN_MT,
MRP_VECATTR_EVENT_MT,
MRP_VECATTR_EVENT_LV,
__MRP_VECATTR_EVENT_MAX
};
struct mrp_skb_cb {
struct mrp_msg_hdr *mh;
struct mrp_vecattr_hdr *vah;
unsigned char attrvalue[];
};
static inline struct mrp_skb_cb *mrp_cb(struct sk_buff *skb)
{
BUILD_BUG_ON(sizeof(struct mrp_skb_cb) >
sizeof_field(struct sk_buff, cb));
return (struct mrp_skb_cb *)skb->cb;
}
enum mrp_applicant_state {
MRP_APPLICANT_INVALID,
MRP_APPLICANT_VO,
MRP_APPLICANT_VP,
MRP_APPLICANT_VN,
MRP_APPLICANT_AN,
MRP_APPLICANT_AA,
MRP_APPLICANT_QA,
MRP_APPLICANT_LA,
MRP_APPLICANT_AO,
MRP_APPLICANT_QO,
MRP_APPLICANT_AP,
MRP_APPLICANT_QP,
__MRP_APPLICANT_MAX
};
#define MRP_APPLICANT_MAX (__MRP_APPLICANT_MAX - 1)
enum mrp_event {
MRP_EVENT_NEW,
MRP_EVENT_JOIN,
MRP_EVENT_LV,
MRP_EVENT_TX,
MRP_EVENT_R_NEW,
MRP_EVENT_R_JOIN_IN,
MRP_EVENT_R_IN,
MRP_EVENT_R_JOIN_MT,
MRP_EVENT_R_MT,
MRP_EVENT_R_LV,
MRP_EVENT_R_LA,
MRP_EVENT_REDECLARE,
MRP_EVENT_PERIODIC,
__MRP_EVENT_MAX
};
#define MRP_EVENT_MAX (__MRP_EVENT_MAX - 1)
enum mrp_tx_action {
MRP_TX_ACTION_NONE,
MRP_TX_ACTION_S_NEW,
MRP_TX_ACTION_S_JOIN_IN,
MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
MRP_TX_ACTION_S_IN_OPTIONAL,
MRP_TX_ACTION_S_LV,
};
struct mrp_attr {
struct rb_node node;
enum mrp_applicant_state state;
u8 type;
u8 len;
unsigned char value[];
};
enum mrp_applications {
MRP_APPLICATION_MVRP,
__MRP_APPLICATION_MAX
};
#define MRP_APPLICATION_MAX (__MRP_APPLICATION_MAX - 1)
struct mrp_application {
enum mrp_applications type;
unsigned int maxattr;
struct packet_type pkttype;
unsigned char group_address[ETH_ALEN];
u8 version;
};
struct mrp_applicant {
struct mrp_application *app;
struct net_device *dev;
struct timer_list join_timer;
struct timer_list periodic_timer;
spinlock_t lock;
struct sk_buff_head queue;
struct sk_buff *pdu;
struct rb_root mad;
struct rcu_head rcu;
bool active;
};
struct mrp_port {
struct mrp_applicant __rcu *applicants[MRP_APPLICATION_MAX + 1];
struct rcu_head rcu;
};
int mrp_register_application(struct mrp_application *app);
void mrp_unregister_application(struct mrp_application *app);
int mrp_init_applicant(struct net_device *dev, struct mrp_application *app);
void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *app);
int mrp_request_join(const struct net_device *dev,
const struct mrp_application *app,
const void *value, u8 len, u8 type);
void mrp_request_leave(const struct net_device *dev,
const struct mrp_application *app,
const void *value, u8 len, u8 type);
#endif /* _NET_MRP_H */