================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xd5/0x140 net/bluetooth/l2cap_sock.c:1684 Read of size 8 at addr ffff88805d7ce188 by task kworker/u9:1/5168 CPU: 0 UID: 0 PID: 5168 Comm: kworker/u9:1 Not tainted 6.16.0-rc5-next-20250710-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: hci3 hci_rx_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 l2cap_sock_ready_cb+0xd5/0x140 net/bluetooth/l2cap_sock.c:1684 l2cap_chan_ready net/bluetooth/l2cap_core.c:1263 [inline] l2cap_le_start+0xb0d/0x13b0 net/bluetooth/l2cap_core.c:1375 l2cap_conn_ready net/bluetooth/l2cap_core.c:1628 [inline] l2cap_connect_cfm+0x6be/0x1040 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm+0x92/0x140 include/net/bluetooth/hci_core.h:2036 le_conn_complete_evt+0xcd3/0x1220 net/bluetooth/hci_event.c:5755 hci_le_conn_complete_evt+0x187/0x450 net/bluetooth/hci_event.c:5781 hci_event_func net/bluetooth/hci_event.c:7512 [inline] hci_event_packet+0x78f/0x1200 net/bluetooth/hci_event.c:7569 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4068 process_one_work kernel/workqueue.c:3239 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8121: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4365 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2233 sk_alloc+0x3a/0x370 net/core/sock.c:2289 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1894 [inline] l2cap_sock_create+0x147/0x300 net/bluetooth/l2cap_sock.c:1936 bt_sock_create+0x160/0x240 net/bluetooth/af_bluetooth.c:135 __sock_create+0x4b3/0x9f0 net/socket.c:1589 sock_create net/socket.c:1647 [inline] __sys_socket_create net/socket.c:1684 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1731 __do_sys_socket net/socket.c:1745 [inline] __se_sys_socket net/socket.c:1743 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8120: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x18e/0x440 mm/slub.c:4879 sk_prot_free net/core/sock.c:2272 [inline] __sk_destruct+0x4e1/0x660 net/core/sock.c:2367 l2cap_sock_release+0x158/0x1d0 net/bluetooth/l2cap_sock.c:1435 __sock_release net/socket.c:649 [inline] sock_close+0xc0/0x240 net/socket.c:1439 __fput+0x449/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805d7ce000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff88805d7ce000, ffff88805d7ce800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d7c8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a442000 0000000000000000 dead000000000001 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000175f201 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 5845, tgid 5845 (syz-executor), ts 88982926619, free_ts 88981144948 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kvmalloc_node_noprof+0x429/0x5f0 mm/slub.c:5052 kvmalloc_array_node_noprof include/linux/slab.h:1065 [inline] __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:471 [inline] ptr_ring_init_noprof include/linux/ptr_ring.h:489 [inline] page_pool_init net/core/page_pool.c:266 [inline] page_pool_create_percpu+0x32a/0xbe0 net/core/page_pool.c:345 nsim_create_page_pool drivers/net/netdevsim/netdev.c:382 [inline] nsim_init_napi drivers/net/netdevsim/netdev.c:405 [inline] nsim_open+0x3ba/0x860 drivers/net/netdevsim/netdev.c:460 __dev_open+0x470/0x880 net/core/dev.c:1681 __dev_change_flags+0x1ea/0x6d0 net/core/dev.c:9496 netif_change_flags+0x88/0x1a0 net/core/dev.c:9559 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3143 rtnl_changelink net/core/rtnetlink.c:3761 [inline] __rtnl_newlink net/core/rtnetlink.c:3920 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2551 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:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 discard_slab mm/slub.c:2753 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3218 put_cpu_partial+0x17c/0x250 mm/slub.c:3293 __slab_free+0x2d5/0x3c0 mm/slub.c:4550 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4281 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:659 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4392 rtmsg_ifinfo_event net/core/rtnetlink.c:4434 [inline] rtnetlink_event+0x1b7/0x270 net/core/rtnetlink.c:7006 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline] call_netdevice_notifiers net/core/dev.c:2280 [inline] netif_change_name+0x5e9/0x960 net/core/dev.c:1488 do_setlink+0x9f6/0x41c0 net/core/rtnetlink.c:3123 rtnl_changelink net/core/rtnetlink.c:3761 [inline] __rtnl_newlink net/core/rtnetlink.c:3920 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 Memory state around the buggy address: ffff88805d7ce080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d7ce100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805d7ce180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805d7ce200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d7ce280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================