================================================================== BUG: KASAN: null-ptr-deref in atomic_sub_return include/asm-generic/atomic-instrumented.h:159 [inline] BUG: KASAN: null-ptr-deref in atomic_dec_return include/linux/atomic-fallback.h:455 [inline] BUG: KASAN: null-ptr-deref in dst_release net/core/dst.c:174 [inline] BUG: KASAN: null-ptr-deref in dst_release+0x2a/0xb0 net/core/dst.c:169 Write of size 4 at addr 000000000000013c by task kworker/u4:2/212 CPU: 1 PID: 212 Comm: kworker/u4:2 Not tainted 5.2.0-rc1+ #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 __kasan_report.cold+0x5/0x40 mm/kasan/report.c:321 kasan_report+0x12/0x20 mm/kasan/common.c:614 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_write+0x14/0x20 mm/kasan/common.c:100 atomic_sub_return include/asm-generic/atomic-instrumented.h:159 [inline] atomic_dec_return include/linux/atomic-fallback.h:455 [inline] dst_release net/core/dst.c:174 [inline] dst_release+0x2a/0xb0 net/core/dst.c:169 dst_cache_destroy net/core/dst_cache.c:164 [inline] dst_cache_destroy+0xd3/0x1b0 net/core/dst_cache.c:156 ipip6_dev_free+0x19/0x50 net/ipv6/sit.c:1360 netdev_run_todo+0x48b/0x7c0 net/core/dev.c:8968 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:116 sit_exit_batch_net+0x565/0x750 net/ipv6/sit.c:1896 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:157 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:553 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 ==================================================================