INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 19414 Comm: syz-executor0 Not tainted 4.17.0-rc4+ #43 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_sys_pread64 fs/read_write.c:636 [inline] __se_sys_pread64 fs/read_write.c:633 [inline] __x64_sys_pread64+0x97/0xf0 fs/read_write.c:633 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f5307b7ec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 RAX: ffffffffffffffda RBX: 00007f5307b7f6d4 RCX: 0000000000455979 RDX: 0000000000000062 RSI: 0000000020000080 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004bc R14: 00000000006fb240 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 ffff8801b14920c0 by task syz-executor0/19487 CPU: 1 PID: 19487 Comm: syz-executor0 Not tainted 4.17.0-rc4+ #43 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_sys_pread64 fs/read_write.c:636 [inline] __se_sys_pread64 fs/read_write.c:633 [inline] __x64_sys_pread64+0x97/0xf0 fs/read_write.c:633 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f5307b7ec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 RAX: ffffffffffffffda RBX: 00007f5307b7f6d4 RCX: 0000000000455979 RDX: 0000000000000062 RSI: 0000000020000080 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004bc R14: 00000000006fb240 R15: 0000000000000000 Allocated by task 19487: 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_ioctl+0x2a/0x40 drivers/net/tun.c:3161 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 19527: 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 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801b14920c0 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff8801b14920c0, ffff8801b14930c0) The buggy address belongs to the page: page:ffffea0006c52480 count:1 mapcount:0 mapping:ffff8801b14920c0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801b14920c0 0000000000000000 0000000100000001 raw: ffffea0007319d20 ffffea00061225a0 ffff8801da800dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b1491f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801b1492000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801b1492080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801b1492100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b1492180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================