KASAN: null-ptr-deref Write in fib6_purge

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KASAN: null-ptr-deref Write in fib6_purge_rt net				18	2211d	2234d	12/29	fixed on 2019/06/18 17:49
linux-4.19	KASAN: null-ptr-deref Write in fib6_purge_rt				1	1555d	1555d	0/1	auto-closed as invalid on 2021/07/20 04:23

================================================================== BUG: KASAN: null-ptr-deref in fib6_drop_pcpu_from net/ipv6/ip6_fib.c:921 [inline] BUG: KASAN: null-ptr-deref in fib6_purge_rt+0x1b3/0x5e0 net/ipv6/ip6_fib.c:933 Write of size 8 at addr 00000000000000e7 by task kworker/u4:4/2546 CPU: 0 PID: 2546 Comm: kworker/u4:4 Not tainted 5.2.0-rc5+ #32 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 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:921 [inline] fib6_purge_rt+0x1b3/0x5e0 net/ipv6/ip6_fib.c:933 fib6_del_route net/ipv6/ip6_fib.c:1808 [inline] fib6_del+0xac2/0x10a0 net/ipv6/ip6_fib.c:1839 fib6_clean_node+0x3a5/0x590 net/ipv6/ip6_fib.c:2001 fib6_walk_continue+0x4a9/0x8e0 net/ipv6/ip6_fib.c:1923 fib6_walk+0x9d/0x100 net/ipv6/ip6_fib.c:1971 fib6_clean_tree+0xe0/0x120 net/ipv6/ip6_fib.c:2050 __fib6_clean_all+0x118/0x2a0 net/ipv6/ip6_fib.c:2066 fib6_clean_all+0x2b/0x40 net/ipv6/ip6_fib.c:2077 rt6_sync_down_dev+0x134/0x150 net/ipv6/route.c:4165 rt6_disable_ip+0x27/0x5f0 net/ipv6/route.c:4170 addrconf_ifdown+0xa2/0x1220 net/ipv6/addrconf.c:3705 addrconf_notify+0x5db/0x2270 net/ipv6/addrconf.c:3630 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95 __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] dev_close_many+0x33f/0x6f0 net/core/dev.c:1518 rollback_registered_many+0x43b/0xfc0 net/core/dev.c:8183 unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9314 unregister_netdevice_many net/core/dev.c:9313 [inline] default_device_exit_batch+0x34e/0x410 net/core/dev.c:9783 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 ==================================================================