================================================================== BUG: KASAN: slab-use-after-free in __hci_acl_create_connection_sync+0x6e4/0x9c0 net/bluetooth/hci_sync.c:6518 Write of size 2 at addr ffff888040a66036 by task kworker/u9:2/20769 CPU: 0 PID: 20769 Comm: kworker/u9:2 Not tainted 6.8.0-rc4-next-20240214-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: hci1 hci_cmd_sync_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __hci_acl_create_connection_sync+0x6e4/0x9c0 net/bluetooth/hci_sync.c:6518 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:306 process_one_work kernel/workqueue.c:3146 [inline] process_scheduled_works+0x9d7/0x1730 kernel/workqueue.c:3226 worker_thread+0x86d/0xd70 kernel/workqueue.c:3307 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Allocated by task 23355: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1d9/0x360 mm/slub.c:4013 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] hci_conn_add+0xc7/0x13a0 net/bluetooth/hci_conn.c:914 hci_conn_add_unset net/bluetooth/hci_conn.c:1016 [inline] hci_connect_acl+0x166/0x4b0 net/bluetooth/hci_conn.c:1632 l2cap_chan_connect+0x5b6/0xeb0 net/bluetooth/l2cap_core.c:7030 l2cap_sock_connect+0x5c9/0x800 net/bluetooth/l2cap_sock.c:256 __sys_connect_file net/socket.c:2048 [inline] __sys_connect+0x2df/0x310 net/socket.c:2065 __do_sys_connect net/socket.c:2075 [inline] __se_sys_connect net/socket.c:2072 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2072 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 20769: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:586 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2122 [inline] slab_free mm/slub.c:4296 [inline] kfree+0x14a/0x380 mm/slub.c:4406 device_release+0x99/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:176 [inline] hci_conn_del+0x8f0/0xc70 net/bluetooth/hci_conn.c:1126 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5361 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:306 process_one_work kernel/workqueue.c:3146 [inline] process_scheduled_works+0x9d7/0x1730 kernel/workqueue.c:3226 worker_thread+0x86d/0xd70 kernel/workqueue.c:3307 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:548 insert_work+0x3e/0x330 kernel/workqueue.c:2143 __queue_work+0xc14/0xec0 kernel/workqueue.c:2296 queue_delayed_work_on+0x15a/0x260 kernel/workqueue.c:2491 l2cap_chan_del+0x291/0x5d0 net/bluetooth/l2cap_core.c:647 l2cap_chan_close+0x38b/0x9f0 l2cap_sock_shutdown+0xa64/0x1020 net/bluetooth/l2cap_sock.c:1344 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1388 __sock_release net/socket.c:659 [inline] sock_close+0xbc/0x240 net/socket.c:1421 __fput+0x429/0x8a0 fs/file_table.c:411 task_work_run+0x24f/0x310 kernel/task_work.c:180 get_signal+0x1673/0x1850 kernel/signal.c:2683 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff888040a66000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 54 bytes inside of freed 4096-byte region [ffff888040a66000, ffff888040a67000) The buggy address belongs to the physical page: page:ffffea0001029800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40a60 head:ffffea0001029800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000840 ffff888014c42140 ffffea00008e0800 dead000000000002 raw: 0000000000000000 0000000080040004 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 0x1d2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 19619, tgid 19610 (syz-executor.1), ts 1298147174445, free_ts 1298104392076 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2191 allocate_slab mm/slub.c:2354 [inline] new_slab+0x84/0x2f0 mm/slub.c:2407 ___slab_alloc+0xc73/0x1260 mm/slub.c:3541 __slab_alloc mm/slub.c:3626 [inline] __slab_alloc_node mm/slub.c:3679 [inline] slab_alloc_node mm/slub.c:3851 [inline] kmalloc_trace+0x267/0x360 mm/slub.c:4008 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:711 [inline] kobject_uevent_env+0x28b/0x8f0 lib/kobject_uevent.c:524 device_del+0x808/0x9e0 drivers/base/core.c:3846 unregister_netdevice_many_notify+0x11fe/0x1700 net/core/dev.c:11152 setup_net+0x8e8/0xca0 net/core/net_namespace.c:367 copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:505 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 copy_namespaces+0x41a/0x490 kernel/nsproxy.c:179 copy_process+0x195e/0x3df0 kernel/fork.c:2511 kernel_clone+0x21e/0x8d0 kernel/fork.c:2915 page last free pid 18721 tgid 18721 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 discard_slab mm/slub.c:2453 [inline] __put_partials+0xeb/0x130 mm/slub.c:2922 put_cpu_partial+0x17c/0x250 mm/slub.c:2997 __slab_free+0x2e8/0x3d0 mm/slub.c:4167 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3814 [inline] slab_alloc_node mm/slub.c:3861 [inline] kmem_cache_alloc_lru+0x175/0x350 mm/slub.c:3880 __d_alloc+0x31/0x700 fs/dcache.c:1624 d_alloc+0x4b/0x190 fs/dcache.c:1704 lookup_one_qstr_excl+0xce/0x260 fs/namei.c:1604 do_unlinkat+0x297/0x830 fs/namei.c:4384 __do_sys_unlink fs/namei.c:4444 [inline] __se_sys_unlink fs/namei.c:4442 [inline] __x64_sys_unlink+0x49/0x60 fs/namei.c:4442 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Memory state around the buggy address: ffff888040a65f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888040a65f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888040a66000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888040a66080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888040a66100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================