BUG: unable to handle page fault for address: ffffffff8a6ef880
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD bc8f067 P4D bc8f067 PUD bc90063 PMD 800000000a6001e1 
Oops: 0003 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 26061 Comm: syz-executor.4 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_sub_return arch/x86/include/asm/atomic.h:178 [inline]
RIP: 0010:arch_atomic_dec_return include/linux/atomic-arch-fallback.h:527 [inline]
RIP: 0010:atomic_dec_return include/asm-generic/atomic-instrumented.h:341 [inline]
RIP: 0010:dst_release net/core/dst.c:174 [inline]
RIP: 0010:dst_release+0x2b/0xe0 net/core/dst.c:169
Code: 55 41 54 49 89 fc 53 e8 b3 84 66 fa 4d 85 e4 74 47 e8 a9 84 66 fa 49 8d 7c 24 40 be 04 00 00 00 e8 4a 8e ab fa b8 ff ff ff ff <f0> 41 0f c1 44 24 40 44 8d 68 ff 31 ff 44 89 ee e8 30 8c 66 fa 45
RSP: 0018:ffffc9000be97bd0 EFLAGS: 00010246
RAX: 00000000ffffffff RBX: dffffc0000000000 RCX: ffffffff870e57e6
RDX: fffffbfff14ddf11 RSI: 0000000000000004 RDI: ffffffff8a6ef880
RBP: ffffe8ffff83fea0 R08: 0000000000000001 R09: ffffffff8a6ef883
R10: fffffbfff14ddf10 R11: 0000000000000000 R12: ffffffff8a6ef840
R13: ffff888048254c48 R14: 0000000000000007 R15: 0000000000000000
FS:  00007efc32e31700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff8a6ef880 CR3: 0000000057b4a000 CR4: 0000000000350ee0
Call Trace:
 dst_cache_destroy net/core/dst_cache.c:160 [inline]
 dst_cache_destroy+0xcb/0x190 net/core/dst_cache.c:152
 ipip6_dev_free net/ipv6/sit.c:1405 [inline]
 sit_init_net+0x88b/0xa80 net/ipv6/sit.c:1927
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x40f/0xa30 net/core/net_namespace.c:333
 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:474
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x8e0 kernel/fork.c:2996
 __do_sys_unshare kernel/fork.c:3064 [inline]
 __se_sys_unshare kernel/fork.c:3062 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3062
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efc32e31188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffca60e7f2f R14: 00007efc32e31300 R15: 0000000000022000
Modules linked in:
CR2: ffffffff8a6ef880
---[ end trace 801c7d126e3162f6 ]---
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_sub_return arch/x86/include/asm/atomic.h:178 [inline]
RIP: 0010:arch_atomic_dec_return include/linux/atomic-arch-fallback.h:527 [inline]
RIP: 0010:atomic_dec_return include/asm-generic/atomic-instrumented.h:341 [inline]
RIP: 0010:dst_release net/core/dst.c:174 [inline]
RIP: 0010:dst_release+0x2b/0xe0 net/core/dst.c:169
Code: 55 41 54 49 89 fc 53 e8 b3 84 66 fa 4d 85 e4 74 47 e8 a9 84 66 fa 49 8d 7c 24 40 be 04 00 00 00 e8 4a 8e ab fa b8 ff ff ff ff <f0> 41 0f c1 44 24 40 44 8d 68 ff 31 ff 44 89 ee e8 30 8c 66 fa 45
RSP: 0018:ffffc9000be97bd0 EFLAGS: 00010246
RAX: 00000000ffffffff RBX: dffffc0000000000 RCX: ffffffff870e57e6
RDX: fffffbfff14ddf11 RSI: 0000000000000004 RDI: ffffffff8a6ef880
RBP: ffffe8ffff83fea0 R08: 0000000000000001 R09: ffffffff8a6ef883
R10: fffffbfff14ddf10 R11: 0000000000000000 R12: ffffffff8a6ef840
R13: ffff888048254c48 R14: 0000000000000007 R15: 0000000000000000
FS:  00007efc32e31700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff8a6ef880 CR3: 0000000057b4a000 CR4: 0000000000350ee0