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
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 1 PID: 4604 Comm: syz-executor7 Not tainted 4.17.0-rc4+ #71
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+0x1b9/0x294 lib/dump_stack.c:113
 assign_lock_key kernel/locking/lockdep.c:729 [inline]
 register_lock_class+0x1dd2/0x2630 kernel/locking/lockdep.c:755
 __lock_acquire+0x1a7/0x5140 kernel/locking/lockdep.c:3319
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:310 [inline]
 ptr_ring_consume include/linux/ptr_ring.h:335 [inline]
 tun_ring_recv drivers/net/tun.c:2143 [inline]
 tun_do_read+0x18b1/0x29f0 drivers/net/tun.c:2182
 tun_chr_read_iter+0xe5/0x1e0 drivers/net/tun.c:2214
 call_read_iter include/linux/fs.h:1778 [inline]
 new_sync_read fs/read_write.c:406 [inline]
 __vfs_read+0x696/0xa50 fs/read_write.c:418
 vfs_read+0x17f/0x3d0 fs/read_write.c:452
 ksys_pread64+0x174/0x1a0 fs/read_write.c:626
 __do_compat_sys_x86_pread arch/x86/ia32/sys_ia32.c:177 [inline]
 __se_compat_sys_x86_pread arch/x86/ia32/sys_ia32.c:174 [inline]
 __ia32_compat_sys_x86_pread+0xc4/0x130 arch/x86/ia32/sys_ia32.c:174
 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
 do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ff8cb9
RSP: 002b:00000000f7ff40ac EFLAGS: 00000282 ORIG_RAX: 00000000000000b4
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000080
RDX: 0000000000000062 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
==================================================================
BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:188 [inline]
BUG: KASAN: use-after-free in __ptr_ring_peek include/linux/ptr_ring.h:176 [inline]
BUG: KASAN: use-after-free in __ptr_ring_consume include/linux/ptr_ring.h:303 [inline]
BUG: KASAN: use-after-free in ptr_ring_consume include/linux/ptr_ring.h:336 [inline]
BUG: KASAN: use-after-free in tun_ring_recv drivers/net/tun.c:2143 [inline]
BUG: KASAN: use-after-free in tun_do_read+0x25a1/0x29f0 drivers/net/tun.c:2182
Read of size 8 at addr ffff8801d64c4040 by task syz-executor4/4686

CPU: 1 PID: 4686 Comm: syz-executor4 Not tainted 4.17.0-rc4+ #71
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+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __read_once_size include/linux/compiler.h:188 [inline]
 __ptr_ring_peek include/linux/ptr_ring.h:176 [inline]
 __ptr_ring_consume include/linux/ptr_ring.h:303 [inline]
 ptr_ring_consume include/linux/ptr_ring.h:336 [inline]
 tun_ring_recv drivers/net/tun.c:2143 [inline]
 tun_do_read+0x25a1/0x29f0 drivers/net/tun.c:2182
 tun_chr_read_iter+0xe5/0x1e0 drivers/net/tun.c:2214
 call_read_iter include/linux/fs.h:1778 [inline]
 new_sync_read fs/read_write.c:406 [inline]
 __vfs_read+0x696/0xa50 fs/read_write.c:418
 vfs_read+0x17f/0x3d0 fs/read_write.c:452
 ksys_pread64+0x174/0x1a0 fs/read_write.c:626
 __do_compat_sys_x86_pread arch/x86/ia32/sys_ia32.c:177 [inline]
 __se_compat_sys_x86_pread arch/x86/ia32/sys_ia32.c:174 [inline]
 __ia32_compat_sys_x86_pread+0xc4/0x130 arch/x86/ia32/sys_ia32.c:174
 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
 do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ffacb9
RSP: 002b:00000000f7ff60ac EFLAGS: 00000282 ORIG_RAX: 00000000000000b4
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000080
RDX: 0000000000000062 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4686:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3682 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3689
 kmalloc_node include/linux/slab.h:554 [inline]
 kvmalloc_node+0x6b/0x100 mm/util.c:421
 kvmalloc include/linux/mm.h:550 [inline]
 kvmalloc_array include/linux/mm.h:566 [inline]
 __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:475 [inline]
 ptr_ring_init include/linux/ptr_ring.h:493 [inline]
 tun_attach+0xa6a/0x12f0 drivers/net/tun.c:837
 tun_set_iff drivers/net/tun.c:2656 [inline]
 __tun_chr_ioctl+0x235a/0x4420 drivers/net/tun.c:2889
 tun_chr_compat_ioctl+0x29/0x30 drivers/net/tun.c:3189
 __do_compat_sys_ioctl fs/compat_ioctl.c:1461 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:1407 [inline]
 __ia32_compat_sys_ioctl+0x221/0x640 fs/compat_ioctl.c:1407
 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
 do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 4714:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 kvfree+0x61/0x70 mm/util.c:440
 ptr_ring_cleanup include/linux/ptr_ring.h:673 [inline]
 tun_cleanup_tx_ring.part.47+0x370/0x590 drivers/net/tun.c:687
 tun_cleanup_tx_ring drivers/net/tun.c:686 [inline]
 tun_detach_all+0x57d/0xcf0 drivers/net/tun.c:787
 tun_net_uninit+0x15/0x20 drivers/net/tun.c:1010
 rollback_registered_many+0xa4c/0xed0 net/core/dev.c:7450
 unregister_netdevice_many+0xf3/0x4c0 net/core/dev.c:8539
 rtnl_delete_link+0x111/0x180 net/core/rtnetlink.c:2677
 rtnl_dellink+0x49d/0xb10 net/core/rtnetlink.c:2731
 rtnetlink_rcv_msg+0x466/0xc10 net/core/rtnetlink.c:4646
 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4664
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 ___sys_sendmsg+0x805/0x940 net/socket.c:2117
 __sys_sendmsg+0x115/0x270 net/socket.c:2155
 __compat_sys_sendmsg net/compat.c:756 [inline]
 __do_compat_sys_sendmsg net/compat.c:763 [inline]
 __se_compat_sys_sendmsg net/compat.c:760 [inline]
 __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:760
 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
 do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff8801d64c4040
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 0 bytes inside of
 4096-byte region [ffff8801d64c4040, ffff8801d64c5040)
The buggy address belongs to the page:
page:ffffea0007593100 count:1 mapcount:0 mapping:ffff8801d64c4040 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801d64c4040 0000000000000000 0000000100000001
raw: ffffea00074f3c20 ffffea00075930a0 ffff8801da800dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d64c3f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d64c3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801d64c4000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff8801d64c4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d64c4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================