================================================================== 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:71 [inline] BUG: KASAN: use-after-free in l2tp_session_delete net/l2tp/l2tp_core.c:1547 [inline] BUG: KASAN: use-after-free in l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1205 [inline] BUG: KASAN: use-after-free in l2tp_tunnel_del_work+0x1bc/0x690 net/l2tp/l2tp_core.c:1237 Write of size 8 at addr ffff88801cb62008 by task kworker/u4:6/4383 CPU: 1 PID: 4383 Comm: kworker/u4:6 Not tainted 5.19.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Workqueue: l2tp l2tp_tunnel_del_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x5b/0x81 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 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:101 [inline] test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline] l2tp_session_delete net/l2tp/l2tp_core.c:1547 [inline] l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1205 [inline] l2tp_tunnel_del_work+0x1bc/0x690 net/l2tp/l2tp_core.c:1237 process_one_work+0x865/0x13d0 kernel/workqueue.c:2289 worker_thread+0x59c/0xec0 kernel/workqueue.c:2436 kthread+0x29d/0x340 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 31200: kasan_save_stack+0x22/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xad/0xe0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:605 [inline] kzalloc include/linux/slab.h:733 [inline] l2tp_session_create+0x32/0xa40 net/l2tp/l2tp_core.c:1583 pppol2tp_connect+0xe8d/0x1990 net/l2tp/l2tp_ppp.c:771 __sys_connect+0xf9/0x130 net/socket.c:1996 __do_sys_connect net/socket.c:2006 [inline] __se_sys_connect net/socket.c:2003 [inline] __x64_sys_connect+0x6e/0xb0 net/socket.c:2003 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:38 kasan_set_track+0x25/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x24/0x40 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3536 [inline] kfree+0xda/0x4e0 mm/slub.c:4584 __sk_destruct+0x47/0x5c0 net/core/sock.c:2067 rcu_do_batch kernel/rcu/tree.c:2578 [inline] rcu_core+0x7b1/0x1880 kernel/rcu/tree.c:2838 __do_softirq+0x29f/0x9c6 kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x9d/0x790 kernel/rcu/tree.c:3126 pppol2tp_release+0x29c/0x420 net/l2tp/l2tp_ppp.c:457 __sock_release+0xbb/0x270 net/socket.c:650 sock_close+0x13/0x20 net/socket.c:1365 __fput+0x1f5/0x8c0 fs/file_table.c:317 task_work_run+0xc4/0x160 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:294 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:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x9d/0x790 kernel/rcu/tree.c:3126 pppol2tp_release+0x29c/0x420 net/l2tp/l2tp_ppp.c:457 __sock_release+0xbb/0x270 net/socket.c:650 sock_close+0x13/0x20 net/socket.c:1365 __fput+0x1f5/0x8c0 fs/file_table.c:317 task_work_run+0xc4/0x160 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:294 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 ffff88801cb62000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 8 bytes inside of 1024-byte region [ffff88801cb62000, ffff88801cb62400) The buggy address belongs to the physical page: page:ffffea000072d800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1cb60 head:ffffea000072d800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011041dc0 raw: 0000000000000000 0000000080100010 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 3884, tgid 3884 (sshd), ts 59248768246, free_ts 59219436869 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x1298/0x3b80 mm/page_alloc.c:4202 __alloc_pages+0x1cb/0x520 mm/page_alloc.c:5430 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x9c4/0xe20 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x2d3/0x370 mm/slub.c:4979 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x8e/0x270 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1426 [inline] __tcp_send_ack.part.0+0x61/0x6d0 net/ipv4/tcp_output.c:3945 tcp_recvmsg_locked+0x593/0x2000 net/ipv4/tcp.c:2525 tcp_recvmsg+0xdf/0x490 net/ipv4/tcp.c:2555 inet_recvmsg+0xf4/0x490 net/ipv4/af_inet.c:850 sock_recvmsg_nosec net/socket.c:995 [inline] sock_recvmsg net/socket.c:1013 [inline] sock_recvmsg net/socket.c:1009 [inline] sock_read_iter+0x2b4/0x3f0 net/socket.c:1086 call_read_iter include/linux/fs.h:2052 [inline] new_sync_read+0x413/0x510 fs/read_write.c:401 vfs_read+0x37c/0x4b0 fs/read_write.c:482 ksys_read+0x16f/0x1c0 fs/read_write.c:620 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page+0x1d/0x6a0 mm/page_alloc.c:3438 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+0xa6/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x20c/0x3b0 mm/slub.c:3268 getname_flags.part.0+0x4a/0x440 fs/namei.c:139 vfs_fstatat+0x39/0x70 fs/stat.c:254 __do_sys_newfstatat+0x72/0xd0 fs/stat.c:425 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: ffff88801cb61f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801cb61f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801cb62000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801cb62080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801cb62100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================