================================================================== BUG: KASAN: use-after-free in xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:208 [inline] BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x4e0/0x560 net/ipv6/xfrm6_tunnel.c:303 Read of size 8 at addr ffff888196cb00b8 by task kworker/0:7/29582 CPU: 0 PID: 29582 Comm: kworker/0:7 Not tainted 4.14.156-syzkaller #0 Workqueue: events xfrm_state_gc_task Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe5/0x154 lib/dump_stack.c:58 print_address_description+0x60/0x226 mm/kasan/report.c:187 __kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316 xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:208 [inline] xfrm6_tunnel_destroy+0x4e0/0x560 net/ipv6/xfrm6_tunnel.c:303 xfrm_state_gc_destroy net/xfrm/xfrm_state.c:449 [inline] xfrm_state_gc_task+0x3d6/0x550 net/xfrm/xfrm_state.c:470 process_one_work+0x7f1/0x1580 kernel/workqueue.c:2134 worker_thread+0xdd/0xdf0 kernel/workqueue.c:2271 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Allocated by task 9942: save_stack mm/kasan/common.c:76 [inline] set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc.part.0+0x53/0xc0 mm/kasan/common.c:501 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] ops_init+0xee/0x3f0 net/core/net_namespace.c:108 setup_net+0x259/0x550 net/core/net_namespace.c:295 copy_net_ns+0x195/0x480 net/core/net_namespace.c:419 create_new_namespaces+0x373/0x760 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xa5/0x1e0 kernel/nsproxy.c:206 SYSC_unshare kernel/fork.c:2543 [inline] SyS_unshare+0x34e/0x6c0 kernel/fork.c:2493 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 0xffffffffffffffff Freed by task 4158: save_stack mm/kasan/common.c:76 [inline] set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x164/0x210 mm/kasan/common.c:463 slab_free_hook mm/slub.c:1407 [inline] slab_free_freelist_hook mm/slub.c:1458 [inline] slab_free mm/slub.c:3039 [inline] kfree+0x108/0x3a0 mm/slub.c:3976 ops_free net/core/net_namespace.c:132 [inline] ops_free_list.part.0+0x1f9/0x330 net/core/net_namespace.c:154 ops_free_list net/core/net_namespace.c:152 [inline] cleanup_net+0x466/0x870 net/core/net_namespace.c:488 process_one_work+0x7f1/0x1580 kernel/workqueue.c:2134 worker_thread+0xdd/0xdf0 kernel/workqueue.c:2271 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 0xffffffffffffffff The buggy address belongs to the object at ffff888196cb0000 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 184 bytes inside of 8192-byte region [ffff888196cb0000, ffff888196cb2000) The buggy address belongs to the page: page:ffffea00065b2c00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 0000000000000000 0000000000000000 0000000100030003 raw: dead000000000100 dead000000000200 ffff8881d6402400 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888196caff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888196cb0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888196cb0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888196cb0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888196cb0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================