================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline] BUG: KASAN: use-after-free in l2tp_session_delete+0x21/0x540 net/l2tp/l2tp_core.c:1552 Write of size 8 at addr ffff888052cf5808 by task kworker/u4:7/3689 CPU: 0 PID: 3689 Comm: kworker/u4:7 Not tainted 5.15.110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: l2tp l2tp_tunnel_del_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline] l2tp_session_delete+0x21/0x540 net/l2tp/l2tp_core.c:1552 l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1207 [inline] l2tp_tunnel_del_work+0x1a2/0x340 net/l2tp/l2tp_core.c:1247 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 27998: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] __kmalloc+0x168/0x300 mm/slub.c:4407 kmalloc include/linux/slab.h:596 [inline] kzalloc include/linux/slab.h:721 [inline] l2tp_session_create+0x37/0xb30 net/l2tp/l2tp_core.c:1588 pppol2tp_connect+0xc3d/0x1720 net/l2tp/l2tp_ppp.c:782 __sys_connect_file net/socket.c:1899 [inline] __sys_connect+0x38b/0x410 net/socket.c:1916 __do_sys_connect net/socket.c:1926 [inline] __se_sys_connect net/socket.c:1923 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:1923 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 2962: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xf1/0x270 mm/slub.c:4559 __sk_destruct+0x54/0x840 net/core/sock.c:1933 rcu_do_batch kernel/rcu/tree.c:2509 [inline] rcu_core+0xa15/0x1650 kernel/rcu/tree.c:2749 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:2993 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3073 pppol2tp_release+0x247/0x340 net/l2tp/l2tp_ppp.c:458 __sock_release net/socket.c:649 [inline] sock_close+0xcd/0x230 net/socket.c:1317 __fput+0x3bf/0x890 fs/file_table.c:280 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb Second to last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x118/0x8a0 kernel/rcu/tree.c:3559 neigh_del net/core/neighbour.c:197 [inline] neigh_remove_one+0x4b1/0x5c0 net/core/neighbour.c:218 neigh_forced_gc net/core/neighbour.c:248 [inline] neigh_alloc net/core/neighbour.c:420 [inline] ___neigh_create+0x397/0x21d0 net/core/neighbour.c:614 ip6_finish_output2+0x11a6/0x14f0 net/ipv6/ip6_output.c:123 dst_output include/net/dst.h:449 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xae0/0x13c0 net/ipv6/ndisc.c:508 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3932 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 The buggy address belongs to the object at ffff888052cf5800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 8 bytes inside of 1024-byte region [ffff888052cf5800, ffff888052cf5c00) The buggy address belongs to the page: page:ffffea00014b3c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x52cf0 head:ffffea00014b3c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000d7c200 0000000300000003 ffff888011c41dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5179, ts 161678045886, free_ts 161657342133 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x12c/0x590 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1167 [inline] nlmsg_new include/net/netlink.h:953 [inline] xfrm_send_acquire+0x143/0xf80 net/xfrm/xfrm_user.c:3265 km_query+0xec/0x1d0 net/xfrm/xfrm_state.c:2247 xfrm_state_find+0x21a5/0x2f10 net/xfrm/xfrm_state.c:1164 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2393 [inline] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2438 [inline] xfrm_resolve_and_create_bundle+0x696/0x2950 net/xfrm/xfrm_policy.c:2731 xfrm_lookup_with_ifid+0x31a/0x2420 net/xfrm/xfrm_policy.c:3065 xfrm_lookup net/xfrm/xfrm_policy.c:3194 [inline] xfrm_lookup_route+0x38/0x1a0 net/xfrm/xfrm_policy.c:3205 ip6_dst_lookup_flow+0x13a/0x170 net/ipv6/ip6_output.c:1224 rawv6_sendmsg+0x1086/0x20f0 net/ipv6/raw.c:932 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] __ip6_append_data+0x29c2/0x3f10 net/ipv6/ip6_output.c:1656 ip6_append_data+0x1d6/0x300 net/ipv6/ip6_output.c:1824 rawv6_sendmsg+0x1695/0x20f0 net/ipv6/raw.c:953 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 Memory state around the buggy address: ffff888052cf5700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888052cf5780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888052cf5800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888052cf5880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052cf5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================