================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:680 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:746 Read of size 8 at addr ffff8880296a9320 by task kworker/2:3/6022 CPU: 2 UID: 0 PID: 6022 Comm: kworker/2:3 Not tainted 6.15.0-rc2-syzkaller-00257-gb5c6891b2c5b #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 Workqueue: events l2cap_chan_timeout 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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline] __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:746 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8589: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6861 l2cap_conn_add include/net/bluetooth/hci_core.h:1639 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7052 l2cap_sock_connect+0x3b7/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x104/0x180 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+0x821/0xaa0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x423/0x670 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file+0x13e/0x1a0 net/socket.c:2038 __sys_connect+0x14d/0x170 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8642: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2398 [inline] slab_free mm/slub.c:4656 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4855 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline] l2cap_conn_del+0x59c/0x730 net/bluetooth/l2cap_core.c:1802 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7300 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7293 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0x10b/0x260 net/bluetooth/hci_conn.c:2701 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5225 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2678 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xafb/0x2c30 kernel/exit.c:953 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 kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880296a9000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff8880296a9000, ffff8880296a9400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x296a8 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 ffff88801b442dc0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b442dc0 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000a5aa01 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 5949, tgid 5949 (syz-executor), ts 48591844078, free_ts 48385005230 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3700 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4982 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2468 [inline] allocate_slab mm/slub.c:2632 [inline] new_slab+0x244/0x340 mm/slub.c:2686 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3872 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3962 __slab_alloc_node mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4198 [inline] __do_kmalloc_node mm/slub.c:4340 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4347 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:947 qdisc_create_dflt+0x73/0x430 net/sched/sch_generic.c:1009 attach_one_default_qdisc net/sched/sch_generic.c:1175 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2650 [inline] attach_default_qdiscs net/sched/sch_generic.c:1193 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1252 __dev_open+0x43a/0x7d0 net/core/dev.c:1638 __dev_change_flags+0x55d/0x720 net/core/dev.c:9366 netif_change_flags+0x8d/0x160 net/core/dev.c:9429 do_setlink.constprop.0+0xddf/0x44b0 net/core/rtnetlink.c:3152 rtnl_changelink net/core/rtnetlink.c:3769 [inline] __rtnl_newlink net/core/rtnetlink.c:3928 [inline] rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4065 page last free pid 6000 tgid 6000 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/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:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4217 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:322 getname include/linux/fs.h:2852 [inline] getname_maybe_null include/linux/fs.h:2859 [inline] getname_maybe_null include/linux/fs.h:2856 [inline] vfs_fstatat+0xe1/0xf0 fs/stat.c:363 __do_sys_newfstatat+0xa1/0x130 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880296a9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880296a9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880296a9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880296a9380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880296a9400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================