================================================================== 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 ffff888075d46008 by task kworker/u4:2/33 CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 6.2.0-rc1-next-20221226-syzkaller #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:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xc0/0xf0 mm/kasan/report.c:517 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:308 Allocated by task 2986: 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:376 [inline] ____kasan_kmalloc mm/kasan/common.c:335 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:968 [inline] __kmalloc+0x5a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [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:518 ____kasan_slab_free mm/kasan/common.c:241 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:205 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x3b0 mm/slub.c:3800 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+0x4d/0x750 net/core/sock.c:2133 sk_destruct net/core/sock.c:2181 [inline] __sk_free+0x175/0x460 net/core/sock.c:2192 sk_free+0x7c/0xa0 net/core/sock.c:2203 sock_put include/net/sock.h:1991 [inline] pppol2tp_put_sk+0x9f/0xd0 net/l2tp/l2tp_ppp.c:401 rcu_do_batch kernel/rcu/tree.c:2246 [inline] rcu_core+0x837/0x1950 kernel/rcu/tree.c:2506 __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:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2755 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:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2755 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 ffff888075d46000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 8 bytes inside of 1024-byte region [ffff888075d46000, ffff888075d46400) The buggy address belongs to the physical page: page:ffffea0001d75000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75d40 head:ffffea0001d75000 order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 ksm flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012441dc0 ffffea0001fb7c00 dead000000000003 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 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7, tgid 7 (kworker/0:0), ts 77183392530, free_ts 77164396748 prep_new_page mm/page_alloc.c:2546 [inline] get_page_from_freelist+0x119e/0x2a80 mm/page_alloc.c:4298 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5564 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2282 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x1a4/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:988 kmalloc_reserve net/core/skbuff.c:492 [inline] __alloc_skb+0xe9/0x310 net/core/skbuff.c:565 alloc_skb include/linux/skbuff.h:1270 [inline] nlmsg_new include/net/netlink.h:1002 [inline] inet6_rt_notify+0xf0/0x2b0 net/ipv6/route.c:6172 fib6_add_rt2node net/ipv6/ip6_fib.c:1251 [inline] fib6_add+0x26eb/0x3f20 net/ipv6/ip6_fib.c:1477 __ip6_ins_rt net/ipv6/route.c:1302 [inline] ip6_ins_rt+0xb6/0x110 net/ipv6/route.c:1312 __ipv6_ifa_notify+0x8c7/0xb60 net/ipv6/addrconf.c:6157 ipv6_ifa_notify net/ipv6/addrconf.c:6196 [inline] addrconf_dad_completed+0x133/0xda0 net/ipv6/addrconf.c:4209 addrconf_dad_begin net/ipv6/addrconf.c:4014 [inline] addrconf_dad_work+0x820/0x12d0 net/ipv6/addrconf.c:4116 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1448 [inline] free_pcp_prepare+0x4d0/0x9e0 mm/page_alloc.c:1498 free_unref_page_prepare mm/page_alloc.c:3384 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3479 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:307 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook mm/slab.h:761 [inline] slab_alloc_node mm/slub.c:3452 [inline] kmem_cache_alloc_node+0x1f1/0x460 mm/slub.c:3497 __alloc_skb+0x216/0x310 net/core/skbuff.c:552 alloc_skb include/linux/skbuff.h:1270 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1202 [inline] netlink_sendmsg+0x9a6/0xe10 net/netlink/af_netlink.c:1907 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 __sys_sendto+0x23a/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xe1/0x1b0 net/socket.c:2125 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 Memory state around the buggy address: ffff888075d45f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888075d45f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888075d46000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888075d46080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888075d46100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================