================================================================== 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 ffff8880497a6036 by task kworker/u9:3/5105 CPU: 1 PID: 5105 Comm: kworker/u9:3 Not tainted 6.8.0-rc4-next-20240213-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: hci2 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 11049: 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 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline] lowpan_control_write+0x568/0x850 net/bluetooth/6lowpan.c:1129 full_proxy_write+0x119/0x1d0 fs/debugfs/file.c:328 vfs_write+0x2a4/0xcb0 fs/read_write.c:588 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 5105: 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_acl_create_connection_sync+0x622/0x9c0 net/bluetooth/hci_sync.c:6554 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_conn_del+0x388/0x680 net/bluetooth/l2cap_core.c:1758 l2cap_connect_cfm+0x11f/0x1220 net/bluetooth/l2cap_core.c:7224 hci_connect_cfm include/net/bluetooth/hci_core.h:1986 [inline] hci_conn_failed+0x1f6/0x340 net/bluetooth/hci_conn.c:1227 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5361 __hci_acl_create_connection_sync+0x622/0x9c0 net/bluetooth/hci_sync.c:6554 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 The buggy address belongs to the object at ffff8880497a6000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 54 bytes inside of freed 4096-byte region [ffff8880497a6000, ffff8880497a7000) The buggy address belongs to the physical page: page:ffffea000125e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x497a0 head:ffffea000125e800 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 ffffea0000b78200 dead000000000002 raw: 0000000000000000 0000000000040004 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6548, tgid 6547 (syz-executor.2), ts 178627380546, free_ts 178576801617 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+0x34eb/0x3680 mm/page_alloc.c:3347 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4603 __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 really_probe+0x80a/0xc50 drivers/base/dd.c:708 __driver_probe_device+0x1a2/0x3e0 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __driver_attach+0x45f/0x710 drivers/base/dd.c:1216 bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:368 bus_add_driver+0x347/0x620 drivers/base/bus.c:673 driver_register+0x23a/0x320 drivers/base/driver.c:246 usb_gadget_register_driver_owner+0xdd/0x230 drivers/usb/gadget/udc/core.c:1685 page last free pid 4520 tgid 4520 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:2382 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2522 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+0x172/0x350 mm/slub.c:3868 getname_flags+0xbd/0x4f0 fs/namei.c:140 user_path_at_empty+0x2c/0x60 fs/namei.c:2917 do_readlinkat+0x118/0x3b0 fs/stat.c:499 __do_sys_readlink fs/stat.c:532 [inline] __se_sys_readlink fs/stat.c:529 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:529 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Memory state around the buggy address: ffff8880497a5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880497a5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880497a6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880497a6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880497a6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================