========================= WARNING: held lock freed! 6.15.0-syzkaller-07802-g558428921edd #0 Not tainted ------------------------- syz.4.1292/10271 is freeing memory ffff88807b643000-ffff88807b6437ff, with a lock still held there! ffff88807b643258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] ffff88807b643258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0xfc/0x590 net/bluetooth/af_bluetooth.c:279 2 locks held by syz.4.1292/10271: #0: ffff888058d3ca08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff888058d3ca08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff888058d3ca08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffff88807b643258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #1: ffff88807b643258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0xfc/0x590 net/bluetooth/af_bluetooth.c:279 stack backtrace: CPU: 0 UID: 0 PID: 10271 Comm: syz.4.1292 Not tainted 6.15.0-syzkaller-07802-g558428921edd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_freed_lock_bug kernel/locking/lockdep.c:6688 [inline] debug_check_no_locks_freed+0x18b/0x1c0 kernel/locking/lockdep.c:6723 slab_free_hook mm/slub.c:2308 [inline] slab_free mm/slub.c:4642 [inline] kfree+0xfd/0x440 mm/slub.c:4841 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x4e1/0x660 net/core/sock.c:2381 bt_accept_dequeue+0x3ce/0x590 net/bluetooth/af_bluetooth.c:308 l2cap_sock_cleanup_listen+0x2f/0x3e0 net/bluetooth/l2cap_sock.c:1451 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1425 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 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:114 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a8738e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff088fdd88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f7a875b7ba0 RCX: 00007f7a8738e969 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7a875b7ba0 R08: 0000000000000228 R09: 0000001e088fe07f R10: 00007f7a875b7ac0 R11: 0000000000000246 R12: 0000000000030bc2 R13: 00007f7a875b5fa0 R14: ffffffffffffffff R15: 00007fff088fdea0 ================================================================== BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x23d/0x290 kernel/locking/spinlock_debug.c:115 Read of size 4 at addr ffff88807b6431c4 by task syz.4.1292/10271 CPU: 0 UID: 0 PID: 10271 Comm: syz.4.1292 Not tainted 6.15.0-syzkaller-07802-g558428921edd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] do_raw_spin_lock+0x23d/0x290 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] release_sock+0x2f/0x1f0 net/core/sock.c:3765 bt_accept_dequeue+0x512/0x590 net/bluetooth/af_bluetooth.c:312 l2cap_sock_cleanup_listen+0x2f/0x3e0 net/bluetooth/l2cap_sock.c:1451 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1425 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 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:114 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a8738e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff088fdd88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f7a875b7ba0 RCX: 00007f7a8738e969 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7a875b7ba0 R08: 0000000000000228 R09: 0000001e088fe07f R10: 00007f7a875b7ac0 R11: 0000000000000246 R12: 0000000000030bc2 R13: 00007f7a875b5fa0 R14: ffffffffffffffff R15: 00007fff088fdea0 Allocated by task 5151: 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:4327 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2247 sk_alloc+0x3a/0x370 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1891 [inline] l2cap_sock_new_connection_cb+0xe2/0x2b0 net/bluetooth/l2cap_sock.c:1482 l2cap_connect_cfm+0x37a/0x1040 net/bluetooth/l2cap_core.c:7264 hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] hci_remote_features_evt+0x581/0x8e0 net/bluetooth/hci_event.c:3747 hci_event_func net/bluetooth/hci_event.c:7511 [inline] hci_event_packet+0x7e3/0x1200 net/bluetooth/hci_event.c:7565 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4036 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 10271: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x18e/0x440 mm/slub.c:4841 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x4e1/0x660 net/core/sock.c:2381 bt_accept_dequeue+0x3ce/0x590 net/bluetooth/af_bluetooth.c:308 l2cap_sock_cleanup_listen+0x2f/0x3e0 net/bluetooth/l2cap_sock.c:1451 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1425 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 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:114 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807b643000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 452 bytes inside of freed 2048-byte region [ffff88807b643000, ffff88807b643800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7b640 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 ffffea0001ed9001 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 7751, tgid 7750 (syz.4.511), ts 147912177338, free_ts 146505861200 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1710 prep_new_page mm/page_alloc.c:1718 [inline] get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3680 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4346 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] rtmsg_ifinfo_build_skb+0x84/0x260 net/core/rtnetlink.c:4390 unregister_netdevice_many_notify+0x166c/0x2320 net/core/dev.c:12080 rtnl_newlink_create+0x802/0xb00 net/core/rtnetlink.c:3851 __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 page last free pid 7645 tgid 7645 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1254 [inline] __free_frozen_pages+0xc6e/0xe50 mm/page_alloc.c:2717 vfree+0x1a6/0x330 mm/vmalloc.c:3416 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d1/0x2550 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1108 __do_sys_exit_group kernel/exit.c:1119 [inline] __se_sys_exit_group kernel/exit.c:1117 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1117 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 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 Memory state around the buggy address: ffff88807b643080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b643100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807b643180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807b643200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807b643280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================