================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: null-ptr-deref in atomic_dec_return include/asm-generic/atomic-instrumented.h:340 [inline] BUG: KASAN: null-ptr-deref in dst_release net/core/dst.c:174 [inline] BUG: KASAN: null-ptr-deref in dst_release+0x26/0xe0 net/core/dst.c:169 Write of size 4 at addr 0000000000000240 by task syz-executor.3/27293 CPU: 1 PID: 27293 Comm: syz-executor.3 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x13e/0x1d6 lib/dump_stack.c:129 __kasan_report mm/kasan/report.c:423 [inline] kasan_report.cold+0x66/0xdf mm/kasan/report.c:436 check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_dec_return include/asm-generic/atomic-instrumented.h:340 [inline] dst_release net/core/dst.c:174 [inline] dst_release+0x26/0xe0 net/core/dst.c:169 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+0x7d8/0xaa0 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+0x319/0x760 net/core/net_namespace.c:474 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x8e0 kernel/fork.c:2999 __do_sys_unshare kernel/fork.c:3067 [inline] __se_sys_unshare kernel/fork.c:3065 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3065 do_syscall_64+0x31/0xb0 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:00007f80d89ae188 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: 00007fff5f21a6bf R14: 00007f80d89ae300 R15: 0000000000022000 ==================================================================