ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci0: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1497 Read of size 8 at addr ffff888036ef8588 by task kworker/u9:0/26507 CPU: 1 UID: 0 PID: 26507 Comm: kworker/u9:0 Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1497 l2cap_connect_cfm+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7271 hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5755 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5781 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7164 hci_event_func net/bluetooth/hci_event.c:7472 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7529 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 26507: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2247 sk_alloc+0x36/0xc20 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1482 l2cap_connect_cfm+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7271 hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5755 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5781 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7164 hci_event_func net/bluetooth/hci_event.c:7472 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7529 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 27123: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x740/0x980 net/core/sock.c:2381 sk_destruct+0xc2/0xf0 net/core/sock.c:2409 __sk_free+0xf4/0x3e0 net/core/sock.c:2420 sk_free+0x6a/0x90 net/core/sock.c:2431 sock_put include/net/sock.h:1960 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline] l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250 l2cap_sock_cleanup_listen+0x3d/0x2a0 net/bluetooth/l2cap_sock.c:1462 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1425 __sock_release+0xb3/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1391 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888036ef8000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1416 bytes inside of freed 2048-byte region [ffff888036ef8000, ffff888036ef8800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x36ef8 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 ffff88801b842000 0000000000000000 0000000000000001 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842000 0000000000000000 0000000000000001 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000dbbe01 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 0x1d28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 26558, tgid 26558 (syz-executor), ts 3251877721903, free_ts 3251541842272 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 pskb_expand_head+0x238/0x1030 net/core/skbuff.c:2241 netlink_trim+0x22d/0x310 net/netlink/af_netlink.c:1295 netlink_unicast+0xc5/0x7f0 net/netlink/af_netlink.c:1329 nlmsg_unicast include/net/netlink.h:1184 [inline] genlmsg_unicast include/net/genetlink.h:553 [inline] genlmsg_reply include/net/genetlink.h:563 [inline] ctrl_getfamily+0x40a/0x540 net/netlink/genetlink.c:1473 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534 page last free pid 25462 tgid 25462 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4249 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037 mld_send_cr net/ipv6/mcast.c:2163 [inline] mld_ifc_work+0x41f/0xca0 net/ipv6/mcast.c:2702 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888036ef8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888036ef8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888036ef8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888036ef8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888036ef8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x4e9/0xf80 net/bluetooth/l2cap_core.c:7273 Write of size 6 at addr ffff88807930d018 by task kworker/u9:0/26507 CPU: 1 UID: 0 PID: 26507 Comm: kworker/u9:0 Tainted: G B 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 l2cap_connect_cfm+0x4e9/0xf80 net/bluetooth/l2cap_core.c:7273 hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5755 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5781 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7164 hci_event_func net/bluetooth/hci_event.c:7472 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7529 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 26507: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_chan_create+0x44/0x920 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1d0 net/bluetooth/l2cap_sock.c:1900 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1482 l2cap_connect_cfm+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7271 hci_connect_cfm include/net/bluetooth/hci_core.h:2056 [inline] le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5755 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5781 hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7164 hci_event_func net/bluetooth/hci_event.c:7472 [inline] hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7529 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4070 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 27123: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x216/0x2c0 net/bluetooth/l2cap_core.c:515 l2cap_sock_cleanup_listen+0x4d/0x2a0 net/bluetooth/l2cap_sock.c:1465 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1425 __sock_release+0xb3/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1391 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807930d000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 24 bytes inside of freed 2048-byte region [ffff88807930d000, ffff88807930d800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79308 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 ffff88801b842000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001e4c201 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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23444, tgid 23444 (syz-executor), ts 2740312282124, free_ts 2740281625194 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 __alloc_skb+0x166/0x380 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] inet6_ifinfo_notify+0x77/0x150 net/ipv6/addrconf.c:6182 addrconf_notify+0x81a/0x19e0 net/ipv6/addrconf.c:3764 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497 netif_change_flags+0x108/0x160 net/core/dev.c:9526 page last free pid 23566 tgid 23566 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:322 getname include/linux/fs.h:2907 [inline] __do_sys_execve fs/exec.c:2010 [inline] __se_sys_execve fs/exec.c:2005 [inline] __x64_sys_execve+0x74/0xb0 fs/exec.c:2005 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807930cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807930cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807930d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807930d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807930d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================