program: r0 = socket$nl_xfrm(0x10, 0x3, 0x6) sendmsg$nl_xfrm(r0, &(0x7f00000003c0)={0x0, 0x0, &(0x7f0000000380)={&(0x7f0000000000)=@newsa={0x150, 0x10, 0x1, 0x0, 0x0, {{@in=@loopback, @in=@loopback, 0x0, 0x0, 0x0, 0x0, 0x2, 0x20, 0x20}, {@in=@loopback, 0xbe3412, 0x32}, @in=@loopback, {}, {}, {}, 0x0, 0x1, 0x2}, [@algo_aead={0x60, 0x12, {{'rfc4106(gcm(aes))\x00'}, 0xa0, 0x60, "210466d38547aa140db9a200000000c538c7cb7a"}}]}, 0x150}}, 0x0) sendmsg$nl_xfrm(r0, &(0x7f0000000500)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000000)=ANY=[@ANYBLOB="940000002900010000000000000000007f00000100000000000000000000000000be3412020032007f0000020000000000000000000000007f00000100000000000000000000000000000000000000007f0000010000000000000000000000007f000001000000000000000000000000000000000000000002002020000000000000000000000000010000000000000002000000"], 0x94}}, 0x0) [ 164.005615][ T4653] Bluetooth: hci0: command tx timeout [ 164.232761][ T5340] [ 164.234445][ T5340] ============================= [ 164.237062][ T5340] WARNING: suspicious RCU usage [ 164.239521][ T5340] syzkaller #0 Not tainted [ 164.241748][ T5340] ----------------------------- [ 164.243911][ T5340] net/xfrm/xfrm_user.c:1630 suspicious rcu_dereference_check() usage! [ 164.248593][ T5340] [ 164.248593][ T5340] other info that might help us debug this: [ 164.248593][ T5340] [ 164.252945][ T5340] [ 164.252945][ T5340] rcu_scheduler_active = 2, debug_locks = 1 [ 164.256466][ T5340] 1 lock held by syz.0.0/5340: [ 164.258803][ T5340] #0: ffff888012491c50 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x6a/0x90 [ 164.264283][ T5340] [ 164.264283][ T5340] stack backtrace: [ 164.266786][ T5340] CPU: 0 UID: 0 PID: 5340 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 164.266805][ T5340] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 164.266817][ T5340] Call Trace: [ 164.266824][ T5340] [ 164.266832][ T5340] dump_stack_lvl+0xe8/0x150 [ 164.266856][ T5340] lockdep_rcu_suspicious+0x13f/0x1d0 [ 164.266877][ T5340] xfrm_nlmsg_multicast+0x1d8/0x1f0 [ 164.266900][ T5340] xfrm_send_migrate_state+0x870/0xae0 [ 164.266924][ T5340] ? __pfx_xfrm_send_migrate_state+0x10/0x10 [ 164.266943][ T5340] ? xfrm_state_migrate_install+0x192/0x630 [ 164.266962][ T5340] xfrm_do_migrate_state+0x1703/0x1e50 [ 164.266979][ T5340] ? __pfx_xfrm_do_migrate_state+0x10/0x10 [ 164.266987][ T5340] ? rcu_is_watching+0x15/0xb0 [ 164.266998][ T5340] ? apparmor_capable+0x126/0x170 [ 164.267061][ T5340] ? __nla_parse+0x40/0x60 [ 164.267080][ T5340] xfrm_user_rcv_msg+0x7a8/0xf30 [ 164.267097][ T5340] ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [ 164.267127][ T5340] ? _raw_spin_unlock_irqrestore+0x30/0x80 [ 164.267146][ T5340] ? lockdep_hardirqs_on+0x7a/0x110 [ 164.267164][ T5340] netlink_rcv_skb+0x226/0x4a0 [ 164.267174][ T5340] ? __mutex_lock+0x5d4/0x1550 [ 164.267187][ T5340] ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [ 164.267198][ T5340] ? __pfx_netlink_rcv_skb+0x10/0x10 [ 164.267218][ T5340] ? netlink_deliver_tap+0x2e/0x1b0 [ 164.267228][ T5340] ? netlink_deliver_tap+0x2e/0x1b0 [ 164.267241][ T5340] xfrm_netlink_rcv+0x79/0x90 [ 164.267251][ T5340] netlink_unicast+0x7bb/0x940 [ 164.267295][ T5340] netlink_sendmsg+0x813/0xb40 [ 164.267312][ T5340] ? __pfx_netlink_sendmsg+0x10/0x10 [ 164.267325][ T5340] ? aa_sock_msg_perm+0xf1/0x1b0 [ 164.267344][ T5340] ? __pfx_netlink_sendmsg+0x10/0x10 [ 164.267354][ T5340] sock_sendmsg_nosec+0x13a/0x180 [ 164.267370][ T5340] ____sys_sendmsg+0x54e/0x850 [ 164.267384][ T5340] ? __pfx_____sys_sendmsg+0x10/0x10 [ 164.267398][ T5340] ? import_iovec+0x73/0xa0 [ 164.267414][ T5340] ___sys_sendmsg+0x2a5/0x360 [ 164.267424][ T5340] ? __lock_acquire+0x683/0x2cf0 [ 164.267440][ T5340] ? __pfx____sys_sendmsg+0x10/0x10 [ 164.267471][ T5340] ? __fget_files+0x2a/0x420 [ 164.267484][ T5340] ? __fget_files+0x3a2/0x420 [ 164.267502][ T5340] __x64_sys_sendmsg+0x1b1/0x290 [ 164.267517][ T5340] ? __pfx___x64_sys_sendmsg+0x10/0x10 [ 164.267533][ T5340] ? do_user_addr_fault+0xc4a/0x1340 [ 164.267555][ T5340] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 164.267566][ T5340] do_syscall_64+0x174/0x580 [ 164.267579][ T5340] ? trace_irq_disable+0x3b/0x140 [ 164.267594][ T5340] ? clear_bhb_loop+0x40/0x90 [ 164.267609][ T5340] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 164.267622][ T5340] RIP: 0033:0x7f4831f9de99 [ 164.267636][ T5340] 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 [ 164.267646][ T5340] RSP: 002b:00007f482e3f4fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 164.267659][ T5340] RAX: ffffffffffffffda RBX: 00007f4832226090 RCX: 00007f4831f9de99 [ 164.267668][ T5340] RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000003 [ 164.267675][ T5340] RBP: 00007f4832033eaf R08: 0000000000000000 R09: 0000000000000000 [ 164.267681][ T5340] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 164.267687][ T5340] R13: 00007f4832226128 R14: 00007f4832226090 R15: 00007ffd7e8fa098 [ 164.267703][ T5340]