======================================
| [  634.760935][ T2875] ==================================================================
| [ 634.761239][ T2875] BUG: KASAN: wild-memory-access in _copy_to_iter (./arch/x86/include/asm/smap.h:35 ./arch/x86/include/asm/uaccess_64.h:121 ./arch/x86/include/asm/uaccess_64.h:147 lib/iov_iter.c:25 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:185) 
| [  634.761508][ T2875] Read of size 982 at addr 0005088000000000 by task ncdevmem/2875
| [  634.761760][ T2875]
[  634.761855][ T2875] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  634.761857][ T2875] Call Trace:
[  634.761860][ T2875]  <TASK>
[ 634.761861][ T2875] dump_stack_lvl (lib/dump_stack.c:123) 
[ 634.761869][ T2875] ? _copy_to_iter (./arch/x86/include/asm/smap.h:35 ./arch/x86/include/asm/uaccess_64.h:121 ./arch/x86/include/asm/uaccess_64.h:147 lib/iov_iter.c:25 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:185) 
[ 634.761871][ T2875] kasan_report (mm/kasan/report.c:597) 
[ 634.761878][ T2875] ? _copy_to_iter (./arch/x86/include/asm/smap.h:35 ./arch/x86/include/asm/uaccess_64.h:121 ./arch/x86/include/asm/uaccess_64.h:147 lib/iov_iter.c:25 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:185) 
[ 634.761883][ T2875] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[ 634.761887][ T2875] _copy_to_iter (./arch/x86/include/asm/smap.h:35 ./arch/x86/include/asm/uaccess_64.h:121 ./arch/x86/include/asm/uaccess_64.h:147 lib/iov_iter.c:25 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:185) 
[ 634.761891][ T2875] ? find_held_lock (kernel/locking/lockdep.c:5350) 
[ 634.761897][ T2875] ? _copy_from_iter_flushcache (lib/iov_iter.c:180) 
[ 634.761901][ T2875] ? mark_held_locks (kernel/locking/lockdep.c:4325) 
[ 634.761905][ T2875] ? finish_task_switch.isra.0 (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 kernel/sched/sched.h:1531 kernel/sched/core.c:5105 kernel/sched/core.c:5223) 
[ 634.761910][ T2875] ? finish_task_switch.isra.0 (./arch/x86/include/asm/atomic.h:67 ./include/linux/atomic/atomic-arch-fallback.h:2278 ./include/linux/atomic/atomic-instrumented.h:1384 ./include/linux/sched/mm.h:54 ./include/linux/sched/mm.h:83 ./include/linux/sched/mm.h:110 kernel/sched/core.c:5250) 
[ 634.761915][ T2875] __skb_datagram_iter (net/core/datagram.c:440) 
[ 634.761920][ T2875] ? skb_free_datagram (net/core/datagram.c:520) 
[ 634.761924][ T2875] ? validate_chain (kernel/locking/lockdep.c:3801 kernel/locking/lockdep.c:3821 kernel/locking/lockdep.c:3876) 
[ 634.761929][ T2875] skb_copy_datagram_iter (net/core/datagram.c:535) 
[ 634.761933][ T2875] tcp_recvmsg_locked (net/ipv4/tcp.c:2802) 
[ 634.761941][ T2875] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 634.761944][ T2875] ? tcp_update_recv_tstamps (net/ipv4/tcp.c:2613) 
[ 634.761949][ T2875] ? __local_bh_enable_ip (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 kernel/softirq.c:412) 
[ 634.761954][ T2875] tcp_recvmsg (net/ipv4/tcp.c:2906) 
[ 634.761956][ T2875] ? filemap_map_pages (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 mm/filemap.c:3794) 
[ 634.761960][ T2875] ? tcp_recv_timestamp (net/ipv4/tcp.c:2892) 
[ 634.761964][ T2875] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 634.761968][ T2875] ? validate_chain (kernel/locking/lockdep.c:3801 kernel/locking/lockdep.c:3821 kernel/locking/lockdep.c:3876) 
[ 634.761974][ T2875] inet6_recvmsg (net/ipv6/af_inet6.c:680 (discriminator 2)) 
[ 634.761978][ T2875] ? inet6_sk_rebuild_header (net/ipv6/af_inet6.c:667) 
[ 634.761983][ T2875] ____sys_recvmsg (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/sock.h:304 net/socket.c:1069 net/socket.c:1087 net/socket.c:2834) 
[ 634.761988][ T2875] ? kernel_sendmsg (net/socket.c:2812) 
[ 634.761990][ T2875] ? _copy_from_user (./arch/x86/include/asm/smap.h:29 ./arch/x86/include/asm/uaccess_64.h:134 ./arch/x86/include/asm/uaccess_64.h:141 ./include/linux/uaccess.h:178 lib/usercopy.c:18) 
[ 634.761995][ T2875] ? copy_msghdr_from_user (net/socket.c:2554) 
[ 634.761998][ T2875] ? __copy_msghdr (net/socket.c:2540) 
[ 634.762004][ T2875] ___sys_recvmsg (net/socket.c:2877) 
[ 634.762008][ T2875] ? ___sys_sendmsg (net/socket.c:2866) 
[ 634.762011][ T2875] ? __handle_mm_fault (mm/memory.c:6195) 
[ 634.762015][ T2875] ? __pmd_alloc (mm/memory.c:6104) 
[ 634.762022][ T2875] ? lock_vma_under_rcu (./include/linux/rcupdate.h:874 mm/mmap_lock.c:170) 
[ 634.762028][ T2875] __sys_recvmsg (net/socket.c:2909) 
[ 634.762031][ T2875] ? __sys_recvmsg_sock (net/socket.c:2894) 
[ 634.762034][ T2875] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:109 ./arch/x86/include/asm/irqflags.h:151 arch/x86/mm/fault.c:1484 arch/x86/mm/fault.c:1532) 
[ 634.762041][ T2875] ? do_user_addr_fault (./arch/x86/include/asm/atomic.h:93 ./include/linux/atomic/atomic-arch-fallback.h:949 ./include/linux/atomic/atomic-instrumented.h:401 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/mmap_lock.h:143 ./include/linux/mmap_lock.h:267 arch/x86/mm/fault.c:1338) 
[ 634.762047][ T2875] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751) 
[ 634.762052][ T2875] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) 
[ 634.762057][ T2875] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  634.762060][ T2875] RIP: 0033:0x7fc9254e907d
[ 634.762063][ T2875] Code: eb b7 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 41 54 48 83 ec 10 64 8b 04 25 18 00 00 00 85 c0 75 22 b8 2f 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5b 4c 63 e0 48 83 c4 10 4c 89 e0 41 5c c3 66
All code
========
   0:	eb b7                	jmp    0xffffffffffffffb9
   2:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   9:	00 00 00 
   c:	90                   	nop
   d:	f3 0f 1e fa          	endbr64
  11:	41 54                	push   %r12
  13:	48 83 ec 10          	sub    $0x10,%rsp
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 22                	jne    0x45
  23:	b8 2f 00 00 00       	mov    $0x2f,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 5b                	ja     0x8d
  32:	4c 63 e0             	movslq %eax,%r12
  35:	48 83 c4 10          	add    $0x10,%rsp
  39:	4c 89 e0             	mov    %r12,%rax
  3c:	41 5c                	pop    %r12
  3e:	c3                   	ret
  3f:	66                   	data16

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 5b                	ja     0x63
   8:	4c 63 e0             	movslq %eax,%r12
   b:	48 83 c4 10          	add    $0x10,%rsp
   f:	4c 89 e0             	mov    %r12,%rax
  12:	41 5c                	pop    %r12
  14:	c3                   	ret
  15:	66                   	data16
[  634.762066][ T2875] RSP: 002b:00007ffcabbecf10 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
[  634.762070][ T2875] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fc9254e907d
[  634.762072][ T2875] RDX: 0000000002000000 RSI: 00007ffcabbecf40 RDI: 0000000000000008
[  634.762074][ T2875] RBP: 00007ffcabcc89f0 R08: 0000000000000000 R09: 00007ffcabbeaca3
[  634.762076][ T2875] R10: 00007fc9253e91c8 R11: 0000000000000246 R12: 00007ffcabcc8b58


Finger prints:
kasan_report:kasan_check_range:_copy_to_iter:__skb_datagram_iter:skb_copy_datagram_iter