================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x240/0x260 net/bluetooth/l2cap_sock.c:1525 Read of size 8 at addr ffff88807965f5a8 by task kworker/u9:5/5815 CPU: 1 UID: 0 PID: 5815 Comm: kworker/u9:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: hci9 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 l2cap_sock_new_connection_cb+0x240/0x260 net/bluetooth/l2cap_sock.c:1525 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5884 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7499 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5815: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0x10b/0x2a0 net/core/sock.c:2245 sk_alloc+0x36/0xe80 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1e0 net/bluetooth/l2cap_sock.c:1925 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x197c/0x1f60 net/bluetooth/hci_event.c:5858 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5884 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7499 hci_event_func net/bluetooth/hci_event.c:7763 [inline] hci_event_packet+0x51c/0xcd0 net/bluetooth/hci_event.c:7817 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 10754: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6483 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x8ab/0xbb0 net/core/sock.c:2384 sk_destruct+0xc8/0xf0 net/core/sock.c:2412 __sk_free+0xf4/0x3e0 net/core/sock.c:2423 sk_free+0x61/0x90 net/core/sock.c:2434 sock_put include/net/sock.h:2007 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1290 [inline] l2cap_sock_kill+0x176/0x310 net/bluetooth/l2cap_sock.c:1275 l2cap_sock_cleanup_listen+0x3d/0x2d0 net/bluetooth/l2cap_sock.c:1490 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb3/0x260 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807965f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1448 bytes inside of freed 2048-byte region [ffff88807965f000, ffff88807965f800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79658 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 ffff88813fe41000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe41000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001e59601 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5808, tgid 5808 (syz-executor), ts 61886827166, free_ts 61733424097 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5368 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 pskb_expand_head+0x246/0xfe0 net/core/skbuff.c:2315 netlink_trim+0x22d/0x2f0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xd7/0xf50 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xb1/0x290 net/netlink/af_netlink.c:2593 rtnl_notify net/core/rtnetlink.c:964 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4458 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4474 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4461 [inline] rtnetlink_event+0x1b3/0x1f0 net/core/rtnetlink.c:7040 notifier_call_chain+0x99/0x420 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] netif_set_mac_address+0x370/0x4a0 net/core/dev.c:10022 page last free pid 5806 tgid 5806 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4873 __kernfs_new_node+0xd2/0x960 fs/kernfs/dir.c:637 kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:718 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313 sysfs_merge_group+0x194/0x340 fs/sysfs/group.c:382 dpm_sysfs_add+0x237/0x280 drivers/base/power/sysfs.c:704 device_add+0x9ef/0x1950 drivers/base/core.c:3651 nsim_bus_dev_new drivers/net/netdevsim/bus.c:471 [inline] new_device_store+0x40b/0x700 drivers/net/netdevsim/bus.c:191 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 Memory state around the buggy address: ffff88807965f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807965f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807965f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807965f600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807965f680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================