================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:681 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x738/0xe80 kernel/locking/mutex.c:747 Read of size 8 at addr ffff88807b452b20 by task kworker/0:1/10 CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.16.0-rc1-syzkaller-00227-g8909f5f4ecd5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events l2cap_chan_timeout Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] __mutex_lock_common kernel/locking/mutex.c:681 [inline] __mutex_lock+0x738/0xe80 kernel/locking/mutex.c:747 l2cap_chan_timeout+0x63/0x390 net/bluetooth/l2cap_core.c:417 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 11975: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add+0xaa/0x8d0 net/bluetooth/l2cap_core.c:6863 l2cap_chan_connect+0x6c8/0xe30 net/bluetooth/l2cap_core.c:7054 l2cap_sock_connect+0x5c5/0x7a0 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x113/0x180 net/socket.c:3608 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x8fe/0xed0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x2f7/0x610 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file net/socket.c:2038 [inline] __sys_connect+0x313/0x440 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 11769: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0x10d/0x230 net/bluetooth/hci_conn.c:2560 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5250 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline] hci_unregister_dev+0x206/0x500 net/bluetooth/hci_core.c:2691 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807b452800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff88807b452800, ffff88807b452c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7b450 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a441dc0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441dc0 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001ed1401 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 37, tgid 37 (kworker/u8:3), ts 96232265935, free_ts 96113066684 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] neigh_alloc net/core/neighbour.c:473 [inline] ___neigh_create+0x6d5/0x2260 net/core/neighbour.c:607 ip6_finish_output2+0xb4d/0x16a0 net/ipv6/ip6_output.c:132 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:317 [inline] ndisc_send_skb+0xb47/0x1400 net/ipv6/ndisc.c:513 addrconf_dad_completed+0x7ae/0xd60 net/ipv6/addrconf.c:4364 addrconf_dad_work+0xc36/0x14b0 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 page last free pid 5831 tgid 5831 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_noprof+0x21b/0x4e0 mm/slub.c:4334 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0x97/0xaa0 net/sched/sch_generic.c:948 qdisc_create_dflt+0x8e/0x4e0 net/sched/sch_generic.c:1010 attach_one_default_qdisc net/sched/sch_generic.c:1176 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2655 [inline] attach_default_qdiscs net/sched/sch_generic.c:1194 [inline] dev_activate+0x378/0x1150 net/sched/sch_generic.c:1253 __dev_open+0x69c/0x880 net/core/dev.c:1692 __dev_change_flags+0x1ea/0x6d0 net/core/dev.c:9499 netif_change_flags+0x88/0x1a0 net/core/dev.c:9562 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3141 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4055 Memory state around the buggy address: ffff88807b452a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b452a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807b452b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807b452b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b452c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================