================================================================== 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 ffff888031ebc010 by task kworker/u9:1/12700 CPU: 0 UID: 0 PID: 12700 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci4 hci_cmd_sync_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 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:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 51: 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:5358 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/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 51: 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:2692 [inline] slab_free mm/slub.c:6143 [inline] kfree+0x1c1/0x630 mm/slub.c:6461 device_release+0x9e/0x1d0 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/0x1030 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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 ffff888031ebc000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 16 bytes inside of freed 8192-byte region [ffff888031ebc000, ffff888031ebe000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31eb8 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 ffff88813fea9280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fea9280 dead000000000100 dead000000000122 head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000c7ae01 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 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5831, tgid 5831 (syz-executor), ts 71099443527, free_ts 46389790963 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2484 alloc_slab_page mm/slub.c:3267 [inline] allocate_slab+0x83/0x660 mm/slub.c:3458 new_slab mm/slub.c:3516 [inline] ___slab_alloc+0x150/0x6b0 mm/slub.c:4390 __slab_alloc_node mm/slub.c:4456 [inline] slab_alloc_node mm/slub.c:4832 [inline] __do_kmalloc_node mm/slub.c:5237 [inline] __kvmalloc_node_noprof+0x34d/0x8a0 mm/slub.c:6730 kvmalloc_array_node_noprof include/linux/slab.h:1216 [inline] __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline] ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline] wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32 wg_newlink+0x326/0x670 drivers/net/wireguard/device.c:357 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x709/0x7a0 net/socket.c:2206 page last free pid 5490 tgid 5490 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5551 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 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:4515 [inline] slab_alloc_node mm/slub.c:4844 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4896 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6763 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2125 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x503/0x550 net/socket.c:1195 do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1 vfs_writev+0x33c/0x990 fs/read_write.c:1059 do_writev+0x154/0x2e0 fs/read_write.c:1105 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888031ebbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888031ebbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888031ebc000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888031ebc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888031ebc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================