general protection fault, probably for non-canonical address 0xdffffc0000000017: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf] CPU: 0 PID: 10841 Comm: syz-executor.4 Not tainted 5.16.0-rc4-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 80 fe 8b 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:ffffc9000405f308 EFLAGS: 00010207 RAX: 0000000000000017 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88804b088000 RSI: ffffffff87ebac70 RDI: 00000000000000bc RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ff88abf R10: ffffffff87ebac04 R11: 0000000000000000 R12: 0000000000000002 R13: ffff8880131cd6a0 R14: ffffed1002639ade R15: 000000000000004c FS: 0000555555a49400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fadf5146603 CR3: 0000000020088000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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+0x6b9/0x820 net/ipv6/ip6_fib.c:1032 fib6_del_route net/ipv6/ip6_fib.c:1982 [inline] fib6_del+0xa28/0x15d0 net/ipv6/ip6_fib.c:2027 fib6_clean_node+0x393/0x5c0 net/ipv6/ip6_fib.c:2189 fib6_walk_continue+0x400/0x720 net/ipv6/ip6_fib.c:2111 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2159 fib6_clean_tree+0xdb/0x120 net/ipv6/ip6_fib.c:2239 __fib6_clean_all+0x107/0x2a0 net/ipv6/ip6_fib.c:2255 rt6_sync_down_dev net/ipv6/route.c:4893 [inline] rt6_disable_ip+0x829/0x940 net/ipv6/route.c:4898 addrconf_ifdown.isra.0+0xf6/0x1630 net/ipv6/addrconf.c:3726 addrconf_notify+0xeb/0x1ba0 net/ipv6/addrconf.c:3651 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline] call_netdevice_notifiers net/core/dev.c:1945 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1520 unregister_netdevice_many+0x3ff/0x1850 net/core/dev.c:10380 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10337 unregister_netdevice include/linux/netdevice.h:2895 [inline] __tun_detach+0x10ad/0x13d0 drivers/net/tun.c:670 tun_detach drivers/net/tun.c:687 [inline] tun_chr_close+0xc4/0x180 drivers/net/tun.c:3402 __fput+0x286/0x9f0 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:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc3da477adb 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:00007ffff09c72d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007fc3da477adb RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000005 RBP: 00007fc3da5d9960 R08: 0000000000000000 R09: 00007fc3da5dd0b0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000047371 R13: 00007ffff09c73d0 R14: 00007fc3da5d8370 R15: 0000000000000032 Modules linked in: ---[ end trace 98f2a3bf5e755309 ]--- 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 80 fe 8b 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:ffffc9000405f308 EFLAGS: 00010207 RAX: 0000000000000017 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88804b088000 RSI: ffffffff87ebac70 RDI: 00000000000000bc RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ff88abf R10: ffffffff87ebac04 R11: 0000000000000000 R12: 0000000000000002 R13: ffff8880131cd6a0 R14: ffffed1002639ade R15: 000000000000004c FS: 0000555555a49400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fadf5146603 CR3: 0000000020088000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 c1 ea 03 shr $0x3,%rdx 4: 80 3c 1a 00 cmpb $0x0,(%rdx,%rbx,1) 8: 0f 85 19 02 00 00 jne 0x227 e: 4c 8b 38 mov (%rax),%r15 11: 4d 85 ff test %r15,%r15 14: 0f 84 7a ff ff ff je 0xffffff94 1a: e8 80 fe 8b f9 callq 0xf98bfe9f 1f: 49 8d 7f 70 lea 0x70(%r15),%rdi 23: 48 89 f8 mov %rdi,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction 2e: 0f 85 4b 02 00 00 jne 0x27f 34: 49 8b 47 70 mov 0x70(%r15),%rax 38: 48 3b 04 24 cmp (%rsp),%rax 3c: 0f .byte 0xf 3d: 85 52 ff test %edx,-0x1(%rdx)