program: r0 = socket$nl_xfrm(0x10, 0x3, 0x6) sendmsg$nl_xfrm(r0, &(0x7f00000003c0)={0x0, 0x0, &(0x7f0000000380)={&(0x7f0000000000)=ANY=[@ANYBLOB="500100001000010000000000000000007f0000010000edffffff0000000000007f00000100000000000000000000000000000000000000000200202000000000", @ANYRES32=0x0, @ANYRES32=0x0, @ANYBLOB="7f00000100000000000000000000000000be3412320000007f000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000100000002000000000000000000000060001200726663343130362867636d2861657329290000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000a000000060"], 0x150}}, 0x0) sendmsg$nl_xfrm(r0, &(0x7f0000000500)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000000)=ANY=[@ANYBLOB="940000002900010000000000000000007f00000100000000000000000000000000be3412020032007f0000020000000000000000000000007f00000100000000000000000000000000000000000000007f0000010000000000000000000000007f000001000000000000000000000000000000000000000002002020000000000000000000000000010000000000000002"], 0x94}}, 0x0) [ 124.436268][ T5320] [ 124.437764][ T5320] ============================= [ 124.439923][ T5320] WARNING: suspicious RCU usage [ 124.441930][ T5320] syzkaller #0 Not tainted [ 124.443921][ T5320] ----------------------------- [ 124.446448][ T5320] net/xfrm/xfrm_user.c:1630 suspicious rcu_dereference_check() usage! [ 124.450407][ T5320] [ 124.450407][ T5320] other info that might help us debug this: [ 124.450407][ T5320] [ 124.455044][ T5320] [ 124.455044][ T5320] rcu_scheduler_active = 2, debug_locks = 1 [ 124.458766][ T5320] locks held by syz.0.0/5320: 1, last CPU#0: [ 124.461438][ T5320] #0: ffff888033629c90 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x6a/0x90 [ 124.466285][ T5320] [ 124.466285][ T5320] stack backtrace: [ 124.468811][ T5320] CPU: 0 UID: 0 PID: 5320 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 124.472481][ T5320] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 124.476875][ T5320] Call Trace: [ 124.478402][ T5320] [ 124.479721][ T5320] dump_stack_lvl+0xe8/0x150 [ 124.481777][ T5320] lockdep_rcu_suspicious+0x140/0x1d0 [ 124.484148][ T5320] xfrm_nlmsg_multicast+0x1d8/0x1f0 [ 124.486407][ T5320] xfrm_send_migrate_state+0x870/0xae0 [ 124.488716][ T5320] ? __pfx_xfrm_send_migrate_state+0x10/0x10 [ 124.491195][ T5320] ? xfrm_state_migrate_install+0x192/0x630 [ 124.493702][ T5320] xfrm_do_migrate_state+0x1703/0x1e50 [ 124.495993][ T5320] ? __pfx_xfrm_do_migrate_state+0x10/0x10 [ 124.498463][ T5320] ? rcu_is_watching+0x16/0xb0 [ 124.500442][ T5320] ? apparmor_capable+0x126/0x170 [ 124.502557][ T5320] ? __nla_parse+0x40/0x60 [ 124.504442][ T5320] xfrm_user_rcv_msg+0x7a8/0xf30 [ 124.506569][ T5320] ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [ 124.508862][ T5320] ? _raw_spin_unlock_irqrestore+0x30/0x80 [ 124.511298][ T5320] netlink_rcv_skb+0x226/0x4a0 [ 124.513313][ T5320] ? __mutex_lock+0x5d4/0x1550 [ 124.515329][ T5320] ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [ 124.517585][ T5320] ? __pfx_netlink_rcv_skb+0x10/0x10 [ 124.519797][ T5320] ? netlink_deliver_tap+0x2e/0x1b0 [ 124.521987][ T5320] ? netlink_deliver_tap+0x2e/0x1b0 [ 124.524327][ T5320] xfrm_netlink_rcv+0x79/0x90 [ 124.526436][ T5320] netlink_unicast+0x7bd/0x940 [ 124.528438][ T5320] netlink_sendmsg+0x813/0xb40 [ 124.530498][ T5320] ? __pfx_netlink_sendmsg+0x10/0x10 [ 124.532742][ T5320] ? apparmor_socket_sendmsg+0x98/0x360 [ 124.535153][ T5320] ? __pfx_netlink_sendmsg+0x10/0x10 [ 124.537350][ T5320] sock_sendmsg_nosec+0x13a/0x180 [ 124.539487][ T5320] ____sys_sendmsg+0x54e/0x850 [ 124.541583][ T5320] ? __pfx_____sys_sendmsg+0x10/0x10 [ 124.543866][ T5320] ? import_iovec+0x73/0xa0 [ 124.545733][ T5320] ___sys_sendmsg+0x2a5/0x360 [ 124.547783][ T5320] ? __lock_acquire+0x6df/0x2e50 [ 124.549667][ T5320] ? __pfx____sys_sendmsg+0x10/0x10 [ 124.551870][ T5320] ? __fget_files+0x2a/0x420 [ 124.553881][ T5320] ? __fget_files+0x3a2/0x420 [ 124.555908][ T5320] __x64_sys_sendmsg+0x1b1/0x290 [ 124.558359][ T5320] ? __pfx___x64_sys_sendmsg+0x10/0x10 [ 124.560711][ T5320] ? do_user_addr_fault+0xc4c/0x1340 [ 124.562997][ T5320] do_syscall_64+0x166/0x520 [ 124.564962][ T5320] ? trace_irq_disable+0x3b/0x140 [ 124.567148][ T5320] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 124.569750][ T5320] ? clear_bhb_loop+0x70/0xc0 [ 124.571932][ T5320] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 124.574462][ T5320] RIP: 0033:0x7f4d3bd9e159 [ 124.576235][ T5320] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 124.583968][ T5320] RSP: 002b:00007f4d3cc8ffe8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 124.587270][ T5320] RAX: ffffffffffffffda RBX: 00007f4d3c026090 RCX: 00007f4d3bd9e159 [ 124.590293][ T5320] RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000003 [ 124.593373][ T5320] RBP: 00007f4d3be35024 R08: 0000000000000000 R09: 0000000000000000 [ 124.596451][ T5320] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 124.599555][ T5320] R13: 00007f4d3c026128 R14: 00007f4d3c026090 R15: 00007ffe15a4bc78 [ 124.602707][ T5320]