================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline] BUG: KASAN: use-after-free in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline] BUG: KASAN: use-after-free in l2tp_session_delete net/l2tp/l2tp_core.c:1555 [inline] BUG: KASAN: use-after-free in l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1207 [inline] BUG: KASAN: use-after-free in l2tp_tunnel_del_work+0x1e8/0x780 net/l2tp/l2tp_core.c:1239 Write of size 8 at addr ffff888079457808 by task kworker/u4:4/102 CPU: 1 PID: 102 Comm: kworker/u4:4 Not tainted 6.1.0-rc7-syzkaller-00122-g355479c70a48 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: l2tp l2tp_tunnel_del_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x141/0x190 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:102 [inline] test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline] l2tp_session_delete net/l2tp/l2tp_core.c:1555 [inline] l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1207 [inline] l2tp_tunnel_del_work+0x1e8/0x780 net/l2tp/l2tp_core.c:1239 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 15805: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:955 [inline] __kmalloc+0x5a/0xd0 mm/slab_common.c:968 kmalloc include/linux/slab.h:558 [inline] kzalloc include/linux/slab.h:689 [inline] l2tp_session_create+0x3a/0xb70 net/l2tp/l2tp_core.c:1591 pppol2tp_connect+0xfff/0x1a10 net/l2tp/l2tp_ppp.c:771 __sys_connect_file+0x153/0x1a0 net/socket.c:1976 __sys_connect+0x165/0x1a0 net/socket.c:1993 __do_sys_connect net/socket.c:2003 [inline] __se_sys_connect net/socket.c:2000 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:2000 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 15: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3674 l2tp_session_free net/l2tp/l2tp_core.c:163 [inline] l2tp_session_dec_refcount+0x15d/0x3a0 net/l2tp/l2tp_core.c:200 pppol2tp_session_destruct+0xbe/0x100 net/l2tp/l2tp_ppp.c:418 __sk_destruct+0x51/0x710 net/core/sock.c:2122 sk_destruct net/core/sock.c:2167 [inline] __sk_free+0x175/0x460 net/core/sock.c:2178 sk_free+0x7c/0xa0 net/core/sock.c:2189 sock_put include/net/sock.h:1987 [inline] pppol2tp_put_sk+0x9f/0xd0 net/l2tp/l2tp_ppp.c:401 rcu_do_batch kernel/rcu/tree.c:2250 [inline] rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2510 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 pppol2tp_release+0x315/0x560 net/l2tp/l2tp_ppp.c:457 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 pppol2tp_release+0x315/0x560 net/l2tp/l2tp_ppp.c:457 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x1c/0x20 net/socket.c:1365 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888079457800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 8 bytes inside of 1024-byte region [ffff888079457800, ffff888079457c00) The buggy address belongs to the physical page: page:ffffea0001e51400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79450 head:ffffea0001e51400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888012041dc0 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 3729, tgid 3729 (kworker/0:6), ts 188509457070, free_ts 184865002121 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4291 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5558 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x199/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0xdd/0x300 net/core/skbuff.c:509 alloc_skb include/linux/skbuff.h:1267 [inline] nlmsg_new include/net/netlink.h:970 [inline] inet6_rt_notify+0xf0/0x2b0 net/ipv6/route.c:6172 fib6_add_rt2node net/ipv6/ip6_fib.c:1252 [inline] fib6_add+0x26eb/0x3f20 net/ipv6/ip6_fib.c:1478 __ip6_ins_rt net/ipv6/route.c:1302 [inline] ip6_route_add+0x8f/0x150 net/ipv6/route.c:3847 addrconf_add_mroute+0x1e1/0x310 net/ipv6/addrconf.c:2489 addrconf_add_dev+0x156/0x1c0 net/ipv6/addrconf.c:2507 addrconf_dev_config+0x1ec/0x410 net/ipv6/addrconf.c:3382 addrconf_notify+0xee0/0x1c80 net/ipv6/addrconf.c:3635 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2586 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x184/0x210 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x2e2/0x3e0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:968 kmalloc include/linux/slab.h:558 [inline] kzalloc include/linux/slab.h:689 [inline] fib_create_info+0xdc2/0x4ac0 net/ipv4/fib_semantics.c:1451 fib_table_insert+0x199/0x1be0 net/ipv4/fib_trie.c:1236 fib_magic+0x455/0x540 net/ipv4/fib_frontend.c:1098 fib_add_ifaddr+0x49f/0x540 net/ipv4/fib_frontend.c:1142 fib_netdev_event+0x36d/0x6a0 net/ipv4/fib_frontend.c:1480 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] __dev_notify_flags+0x114/0x2c0 net/core/dev.c:8581 Memory state around the buggy address: ffff888079457700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888079457780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888079457800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079457880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079457900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================