================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x1d4/0x200 lib/list_debug.c:62 Read of size 8 at addr ffff88805a8a1558 by task syz.2.2858/27680 CPU: 2 UID: 0 PID: 27680 Comm: syz.2.2858 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 __list_del_entry_valid_or_report+0x1d4/0x200 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:124 [inline] __list_del_entry include/linux/list.h:215 [inline] list_del_init include/linux/list.h:287 [inline] bt_accept_unlink+0x34/0x2e0 net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x1a3/0x3c0 net/bluetooth/l2cap_sock.c:1613 l2cap_chan_del+0xba/0x8f0 net/bluetooth/l2cap_core.c:655 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1787 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7325 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7318 hci_disconn_cfm include/net/bluetooth/hci_core.h:2065 [inline] hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2564 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5294 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:501 hci_unregister_dev+0x227/0x640 net/bluetooth/hci_core.c:2715 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c21bc14a5 Code: Unable to access opcode bytes at 0x7f7c21bc147b. RSP: 002b:00007f7c22a61f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f7c21db5fa0 RCX: 00007f7c21bc14a5 RDX: 00007f7c22a61fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7c21c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f7c21db6038 R14: 00007f7c21db5fa0 R15: 00007ffd9f6638a8 Allocated by task 1126: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] devinet_init_net+0x56/0x910 net/ipv4/devinet.c:2758 ops_init+0x1df/0x5f0 net/core/net_namespace.c:136 setup_net+0x10f/0x380 net/core/net_namespace.c:438 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:570 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3127 __do_sys_unshare kernel/fork.c:3198 [inline] __se_sys_unshare kernel/fork.c:3196 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3196 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 60: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 ops_exit_list net/core/net_namespace.c:198 [inline] ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:251 cleanup_net+0x408/0x890 net/core/net_namespace.c:682 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88805a8a1000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1368 bytes inside of freed 2048-byte region [ffff88805a8a1000, ffff88805a8a1800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a8a0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b842f00 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842f00 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00016a2801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 24025, tgid 24025 (syz-executor), ts 144792961603, free_ts 144790467833 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x247/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4371 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:950 qdisc_create_dflt+0x94/0x490 net/sched/sch_generic.c:1012 attach_one_default_qdisc net/sched/sch_generic.c:1178 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2660 [inline] attach_default_qdiscs net/sched/sch_generic.c:1196 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1255 __dev_open+0x432/0x7c0 net/core/dev.c:1691 __dev_change_flags+0x55d/0x720 net/core/dev.c:9537 netif_change_flags+0x8d/0x160 net/core/dev.c:9600 do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3143 rtnl_changelink net/core/rtnetlink.c:3761 [inline] __rtnl_newlink net/core/rtnetlink.c:3920 [inline] rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4057 page last free pid 24025 tgid 24025 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 discard_slab mm/slub.c:2753 [inline] __put_partials+0x165/0x1c0 mm/slub.c:3218 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4281 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:659 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1055 [inline] netlink_ack+0x15d/0xb80 net/netlink/af_netlink.c:2489 netlink_rcv_skb+0x332/0x420 net/netlink/af_netlink.c:2558 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] __sys_sendto+0x4a3/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805a8a1400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a8a1480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a8a1500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a8a1580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a8a1600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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