================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:664 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x9eb/0xb10 kernel/locking/mutex.c:730 Read of size 8 at addr ffff888025fbdb20 by task kworker/1:4/9039 CPU: 1 UID: 0 PID: 9039 Comm: kworker/1:4 Not tainted 6.14.0-rc3-syzkaller-00079-g87a132e73910 #0 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+0xd9/0x110 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline] __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x9eb/0xb10 kernel/locking/mutex.c:730 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 9266: 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:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6820 l2cap_conn_add include/net/bluetooth/hci_core.h:1618 [inline] l2cap_chan_connect+0x15e8/0x2010 net/bluetooth/l2cap_core.c:7011 l2cap_sock_connect+0x3b8/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x105/0x180 net/socket.c:3615 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x823/0xaa0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x418/0x630 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file+0x13e/0x1a0 net/socket.c:2045 __sys_connect+0x14f/0x170 net/socket.c:2064 __do_sys_connect net/socket.c:2070 [inline] __se_sys_connect net/socket.c:2067 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2067 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5938: 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:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x2c4/0x4d0 mm/slub.c:4757 l2cap_conn_free net/bluetooth/l2cap_core.c:1809 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1821 [inline] l2cap_conn_del+0x5a0/0x730 net/bluetooth/l2cap_core.c:1801 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0x44a/0x790 net/bluetooth/hci_conn.c:2698 hci_dev_close_sync+0x603/0x11a0 net/bluetooth/hci_sync.c:5197 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:482 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2677 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:664 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 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/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888025fbd800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff888025fbd800, ffff888025fbdc00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888025fb9800 pfn:0x25fb8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b042dc0 ffffea00007ca810 ffffea0000ab4210 raw: ffff888025fb9800 0000000000100005 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b042dc0 ffffea00007ca810 ffffea0000ab4210 head: ffff888025fb9800 0000000000100005 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000097ee01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 7841807475, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_slab_page mm/slub.c:2425 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x94/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_node_noprof+0x2f0/0x510 mm/slub.c:4300 kmalloc_array_node_noprof include/linux/slab.h:1018 [inline] blk_mq_alloc_rq_map block/blk-mq.c:3496 [inline] blk_mq_alloc_map_and_rqs+0x2a4/0xec0 block/blk-mq.c:4042 __blk_mq_alloc_map_and_rqs block/blk-mq.c:4064 [inline] __blk_mq_alloc_map_and_rqs+0x128/0x1f0 block/blk-mq.c:4055 __blk_mq_alloc_rq_maps block/blk-mq.c:4588 [inline] blk_mq_alloc_set_map_and_rqs block/blk-mq.c:4619 [inline] blk_mq_alloc_tag_set+0x754/0x1240 block/blk-mq.c:4791 loop_add+0x3bd/0xb60 drivers/block/loop.c:2049 loop_init+0x164/0x270 drivers/block/loop.c:2288 do_one_initcall+0x128/0x700 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1568 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 page_owner free stack trace missing Memory state around the buggy address: ffff888025fbda00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025fbda80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888025fbdb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888025fbdb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025fbdc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================