=============================
WARNING: suspicious RCU usage
4.14.154 #0 Not tainted
-----------------------------
include/linux/radix-tree.h:238 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor.5/21073:
 #0:  (&sb->s_type->i_mutex_key#12){+.+.}, at: [<ffffffff8177534e>] inode_lock include/linux/fs.h:718 [inline]
 #0:  (&sb->s_type->i_mutex_key#12){+.+.}, at: [<ffffffff8177534e>] shmem_add_seals+0x15e/0x1060 mm/shmem.c:2810
 #1:  (&(&mapping->tree_lock)->rlock){-.-.}, at: [<ffffffff81775524>] spin_lock_irq include/linux/spinlock.h:342 [inline]
 #1:  (&(&mapping->tree_lock)->rlock){-.-.}, at: [<ffffffff81775524>] shmem_tag_pins mm/shmem.c:2665 [inline]
 #1:  (&(&mapping->tree_lock)->rlock){-.-.}, at: [<ffffffff81775524>] shmem_wait_for_pins mm/shmem.c:2706 [inline]
 #1:  (&(&mapping->tree_lock)->rlock){-.-.}, at: [<ffffffff81775524>] shmem_add_seals+0x334/0x1060 mm/shmem.c:2822

stack backtrace:
CPU: 0 PID: 21073 Comm: syz-executor.5 Not tainted 4.14.154 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:4665
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 radix_tree_deref_slot include/linux/radix-tree.h:236 [inline]
 shmem_tag_pins mm/shmem.c:2667 [inline]
 shmem_wait_for_pins mm/shmem.c:2706 [inline]
 shmem_add_seals+0x9e0/0x1060 mm/shmem.c:2822
 shmem_fcntl+0xf7/0x130 mm/shmem.c:2857
 do_fcntl+0x190/0xe10 fs/fcntl.c:421
 SYSC_fcntl fs/fcntl.c:463 [inline]
 SyS_fcntl+0xd5/0x110 fs/fcntl.c:448
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a639
RSP: 002b:00007f9325f2fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639
RDX: 0000000000000008 RSI: 0000000000000409 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9325f306d4
R13: 00000000004c1068 R14: 00000000004d3c60 R15: 00000000ffffffff
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=21175 comm=syz-executor.3
IPVS: ftp: loaded support on port[0] = 21
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=21200 comm=syz-executor.3
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21