============================= 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.4/22382: #0: 00000000a921100f (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:747 [inline] #0: 00000000a921100f (&sb->s_type->i_mutex_key#12){+.+.}, at: memfd_add_seals mm/memfd.c:199 [inline] #0: 00000000a921100f (&sb->s_type->i_mutex_key#12){+.+.}, at: memfd_fcntl+0x235/0x1750 mm/memfd.c:249 #1: 00000000669bc20c (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: spin_lock_irq include/linux/spinlock.h:354 [inline] #1: 00000000669bc20c (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_tag_pins mm/memfd.c:42 [inline] #1: 00000000669bc20c (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_wait_for_pins mm/memfd.c:83 [inline] #1: 00000000669bc20c (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_add_seals mm/memfd.c:217 [inline] #1: 00000000669bc20c (&(&(&mapping->i_pages)->xa_lock)->rlock){-.-.}, at: memfd_fcntl+0x4bc/0x1750 mm/memfd.c:249 stack backtrace: CPU: 1 PID: 22382 Comm: syz-executor.4 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: 0033:0x45a639 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:00007f9e08819c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000008 RSI: 0000000000000409 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9e0881a6d4 R13: 00000000004c1068 R14: 00000000004d3c60 R15: 00000000ffffffff device lo entered promiscuous mode device lo left promiscuous mode audit: type=1400 audit(1574009096.208:64): avc: denied { map_read map_write } for pid=22856 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 validate_nla: 58 callbacks suppressed netlink: 'syz-executor.2': attribute type 46 has an invalid length. netlink: 'syz-executor.2': attribute type 46 has an invalid length. netlink: 'syz-executor.2': attribute type 46 has an invalid length. netlink: 'syz-executor.2': attribute type 46 has an invalid length. nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. netlink: 'syz-executor.0': attribute type 46 has an invalid length. netlink: 'syz-executor.0': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.0': attribute type 46 has an invalid length. netlink: 'syz-executor.0': attribute type 46 has an invalid length. capability: warning: `syz-executor.4' uses 32-bit capabilities (legacy support in use) validate_nla: 12 callbacks suppressed netlink: 'syz-executor.0': attribute type 46 has an invalid length. netlink: 'syz-executor.0': attribute type 46 has an invalid length. netlink: 'syz-executor.2': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.2': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length. netlink: 'syz-executor.3': attribute type 46 has an invalid length.