general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] CPU: 0 PID: 25076 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10b/0x390 net/ipv6/ip6_fib.c:978 Code: 48 c1 ea 03 80 3c 1a 00 0f 85 19 02 00 00 4c 8b 38 4d 85 ff 0f 84 7a ff ff ff e8 50 62 ac f9 49 8d 7f 70 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 4b 02 00 00 49 8b 47 70 48 3b 04 24 0f 85 52 ff RSP: 0018:ffffc9000179f2a8 EFLAGS: 00010202 RAX: 000000000000000e RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88807bca54c0 RSI: ffffffff87c86060 RDI: 0000000000000071 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffffff9025f947 R10: ffffffff87c85ff4 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88806e259ca0 R14: ffffed100dc4b39e R15: 0000000000000001 FS: 00000000020a3400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffceb7bf917 CR3: 0000000074cd8000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:960 [inline] fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1021 [inline] fib6_purge_rt+0x6a3/0x810 net/ipv6/ip6_fib.c:1032 fib6_del_route net/ipv6/ip6_fib.c:1983 [inline] fib6_del+0xa92/0x15a0 net/ipv6/ip6_fib.c:2028 fib6_clean_node+0x398/0x5c0 net/ipv6/ip6_fib.c:2190 fib6_walk_continue+0x4aa/0x8e0 net/ipv6/ip6_fib.c:2112 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2160 fib6_clean_tree+0xdb/0x120 net/ipv6/ip6_fib.c:2240 __fib6_clean_all+0x120/0x290 net/ipv6/ip6_fib.c:2256 rt6_sync_down_dev net/ipv6/route.c:4892 [inline] rt6_disable_ip+0x827/0x930 net/ipv6/route.c:4897 addrconf_ifdown.isra.0+0xf6/0x15b0 net/ipv6/addrconf.c:3706 addrconf_notify+0x55c/0x23e0 net/ipv6/addrconf.c:3631 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2121 call_netdevice_notifiers_extack net/core/dev.c:2133 [inline] call_netdevice_notifiers net/core/dev.c:2147 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1722 unregister_netdevice_many+0x3ff/0x1790 net/core/dev.c:10990 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10947 unregister_netdevice include/linux/netdevice.h:2969 [inline] __tun_detach+0x105a/0x13d0 drivers/net/tun.c:670 tun_detach drivers/net/tun.c:687 [inline] tun_chr_close+0xd9/0x180 drivers/net/tun.c:3397 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x272/0x280 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4193eb Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007fff4ad7a290 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00000000004193eb RDX: ffffffffffffffbc RSI: ffffffff817acfce RDI: 0000000000000006 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b32026f8c R10: 000000000000052f R11: 0000000000000293 R12: 000000000056cb00 R13: 000000000056cb00 R14: 000000000056bf80 R15: 00000000001805af Modules linked in: ---[ end trace c4296e422ac72826 ]--- RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10b/0x390 net/ipv6/ip6_fib.c:978 Code: 48 c1 ea 03 80 3c 1a 00 0f 85 19 02 00 00 4c 8b 38 4d 85 ff 0f 84 7a ff ff ff e8 50 62 ac f9 49 8d 7f 70 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 4b 02 00 00 49 8b 47 70 48 3b 04 24 0f 85 52 ff RSP: 0018:ffffc9000179f2a8 EFLAGS: 00010202 RAX: 000000000000000e RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88807bca54c0 RSI: ffffffff87c86060 RDI: 0000000000000071 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffffff9025f947 R10: ffffffff87c85ff4 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88806e259ca0 R14: ffffed100dc4b39e R15: 0000000000000001 FS: 00000000020a3400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffceb7bf917 CR3: 0000000074cd8000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600