audit: type=1400 audit(1575221297.317:66473): avc: denied { net_admin } for pid=16766 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 ================================================================== BUG: KASAN: use-after-free in xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:205 [inline] BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x57c/0x630 net/ipv6/xfrm6_tunnel.c:300 Read of size 8 at addr ffff8801d1c6c2b8 by task kworker/0:2/16277 CPU: 0 PID: 16277 Comm: kworker/0:2 Not tainted 4.9.141+ #23 Workqueue: events xfrm_state_gc_task ffff88018c24faa0 ffffffff81b42e79 ffffea0007471a00 ffff8801d1c6c2b8 0000000000000000 ffff8801d1c6c2b8 ffff8801d4181c0c ffff88018c24fad8 ffffffff815009b8 ffff8801d1c6c2b8 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:205 [inline] [] xfrm6_tunnel_destroy+0x57c/0x630 net/ipv6/xfrm6_tunnel.c:300 [] xfrm_state_gc_destroy net/xfrm/xfrm_state.c:368 [inline] [] xfrm_state_gc_task+0x3ad/0x510 net/xfrm/xfrm_state.c:388 [] process_one_work+0x831/0x15f0 kernel/workqueue.c:2092 [] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Allocated by task 2076: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594 __kmalloc+0x12f/0x310 mm/slub.c:3741 kmalloc include/linux/slab.h:495 [inline] kzalloc include/linux/slab.h:636 [inline] ops_init+0xef/0x3a0 net/core/net_namespace.c:101 setup_net+0x1bc/0x4d0 net/core/net_namespace.c:291 copy_net_ns+0x189/0x330 net/core/net_namespace.c:408 create_new_namespaces+0x501/0x760 kernel/nsproxy.c:106 unshare_nsproxy_namespaces+0xa5/0x1d0 kernel/nsproxy.c:205 SYSC_unshare kernel/fork.c:2263 [inline] SyS_unshare+0x319/0x710 kernel/fork.c:2213 do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137 Freed by task 10612: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kfree+0xfb/0x310 mm/slub.c:3878 ops_free net/core/net_namespace.c:126 [inline] ops_free_list.part.3+0x1ff/0x330 net/core/net_namespace.c:148 ops_free_list net/core/net_namespace.c:146 [inline] cleanup_net+0x490/0x8b0 net/core/net_namespace.c:477 process_one_work+0x831/0x15f0 kernel/workqueue.c:2092 worker_thread+0xd6/0x1140 kernel/workqueue.c:2226 kthread+0x26d/0x300 kernel/kthread.c:211 ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 The buggy address belongs to the object at ffff8801d1c6c200 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 184 bytes inside of 8192-byte region [ffff8801d1c6c200, ffff8801d1c6e200) The buggy address belongs to the page: page:ffffea0007471a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d1c6c180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d1c6c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d1c6c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d1c6c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d1c6c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================