================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2a0 include/net/bluetooth/hci_core.h:1690 Write of size 4 at addr ffff88802c608010 by task kworker/u9:2/5841 CPU: 1 UID: 0 PID: 5841 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci3 hci_cmd_sync_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] hci_conn_drop+0x34/0x2a0 include/net/bluetooth/hci_core.h:1690 hci_cmd_sync_work+0x262/0x400 net/bluetooth/hci_sync.c:334 process_one_work kernel/workqueue.c:3278 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5841: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5412 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] __hci_conn_add+0x3c4/0x1e00 net/bluetooth/hci_conn.c:963 le_conn_complete_evt+0x706/0x1430 net/bluetooth/hci_event.c:5740 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5873 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3278 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 5856: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6242 [inline] kfree+0x1c5/0x640 mm/slub.c:6557 device_release+0xc4/0x1f0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x560 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline] hci_conn_del+0xc36/0x1230 net/bluetooth/hci_conn.c:1240 hci_disconn_complete_evt+0x64e/0x950 net/bluetooth/hci_event.c:3476 hci_event_func net/bluetooth/hci_event.c:7784 [inline] hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3278 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3361 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3442 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88802c608000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 16 bytes inside of freed 8192-byte region [ffff88802c608000, ffff88802c60a000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c608 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe33280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe33280 dead000000000122 0000000000000000 head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 6139, tgid 6138 (syz.0.72), ts 110582778525, free_ts 110465990452 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1848 prep_new_page mm/page_alloc.c:1856 [inline] get_page_from_freelist+0x239b/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x233/0x3d0 mm/page_alloc.c:5202 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x339/0x3d0 mm/slub.c:7247 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5291 [inline] __kmalloc_noprof+0x474/0x760 mm/slub.c:5304 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snd_seq_oss_readq_new+0x86/0x230 sound/core/seq/oss/seq_oss_readq.c:41 snd_seq_oss_open+0x81e/0xfc0 sound/core/seq/oss/seq_oss_init.c:226 odev_open+0x67/0xa0 sound/core/seq/oss/seq_oss.c:128 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411 do_dentry_open+0x785/0x14e0 fs/open.c:949 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1366 page last free pid 5845 tgid 5845 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1392 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2933 __slab_free+0x274/0x2c0 mm/slub.c:5605 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] __kmalloc_cache_node_noprof+0x391/0x6b0 mm/slub.c:5420 kmalloc_node_noprof include/linux/slab.h:1077 [inline] __get_vm_area_node+0x13f/0x300 mm/vmalloc.c:3215 __vmalloc_node_range_noprof+0x36a/0x1750 mm/vmalloc.c:4024 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline] do_ip6t_get_ctl+0xabd/0x1230 net/ipv6/netfilter/ip6_tables.c:1677 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1fd/0x2b0 net/ipv6/ipv6_sockglue.c:1464 do_sock_getsockopt+0x2d3/0x3f0 net/socket.c:2441 __sys_getsockopt net/socket.c:2470 [inline] __do_sys_getsockopt net/socket.c:2477 [inline] __se_sys_getsockopt net/socket.c:2474 [inline] __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2474 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88802c607f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802c607f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802c608000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802c608080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c608100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================