============================= WARNING: suspicious RCU usage 4.19.84 #0 Not tainted ----------------------------- include/linux/radix-tree.h:241 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.0/14627: #0: 000000000fbfdf9f (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:747 [inline] #0: 000000000fbfdf9f (&sb->s_type->i_mutex_key#12){+.+.}, at: memfd_add_seals mm/memfd.c:199 [inline] #0: 000000000fbfdf9f (&sb->s_type->i_mutex_key#12){+.+.}, at: memfd_fcntl+0x235/0x1750 mm/memfd.c:249 #1: 0000000075cf7786 (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] #1: 0000000075cf7786 (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_tag_pins mm/memfd.c:42 [inline] #1: 0000000075cf7786 (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_wait_for_pins mm/memfd.c:83 [inline] #1: 0000000075cf7786 (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_add_seals mm/memfd.c:217 [inline] #1: 0000000075cf7786 (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_fcntl+0x4bc/0x1750 mm/memfd.c:249 stack backtrace: CPU: 1 PID: 14627 Comm: syz-executor.0 Not tainted 4.19.84 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:4539 radix_tree_deref_slot include/linux/radix-tree.h:241 [inline] radix_tree_deref_slot include/linux/radix-tree.h:239 [inline] memfd_tag_pins mm/memfd.c:44 [inline] memfd_wait_for_pins mm/memfd.c:83 [inline] memfd_add_seals mm/memfd.c:217 [inline] memfd_fcntl+0xfdf/0x1750 mm/memfd.c:249 do_fcntl+0x200/0x1020 fs/fcntl.c:421 __do_sys_fcntl fs/fcntl.c:463 [inline] __se_sys_fcntl fs/fcntl.c:448 [inline] __x64_sys_fcntl+0x16d/0x1e0 fs/fcntl.c:448 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a669 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4a42e18c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a669 RDX: 0000000000000008 RSI: 0000000000000409 RDI: 0000000000000006 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4a42e196d4 R13: 00000000004c10a8 R14: 00000000004d3ca0 R15: 00000000ffffffff audit: type=1800 audit(1573956385.184:129): pid=14655 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=collect_data cause=failed comm="syz-executor.0" name="bus" dev="sda1" ino=16833 res=0 audit: type=1800 audit(1573956386.754:130): pid=14717 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=collect_data cause=failed comm="syz-executor.0" name="memory.swap.current" dev="sda1" ino=16658 res=0 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.