=========================================[ 1529.616733][T18741] ================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xe3/0x180 net/bluetooth/l2cap_sock.c:1788 Read of size 8 at addr ffff8880405c4200 by task kworker/u9:4/18741 CPU: 0 UID: 0 PID: 18741 Comm: kworker/u9:4 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Workqueue: hci2 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_ready_cb+0xe3/0x180 net/bluetooth/l2cap_sock.c:1788 l2cap_le_start+0x257/0x1910 net/bluetooth/l2cap_core.c:1420 l2cap_conn_ready net/bluetooth/l2cap_core.c:1673 [inline] l2cap_connect_cfm+0x950/0x1620 net/bluetooth/l2cap_core.c:7575 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2137 le_conn_complete_evt+0x1034/0x1580 net/bluetooth/hci_event.c:5856 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5882 hci_event_func net/bluetooth/hci_event.c:7784 [inline] hci_event_packet+0x67a/0xf10 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1020 net/bluetooth/hci_core.c:4042 process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379 process_scheduled_works kernel/workqueue.c:3462 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 27624: 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] __do_kmalloc_node mm/slub.c:5339 [inline] __kmalloc_noprof+0x415/0x790 mm/slub.c:5364 _kmalloc_noprof include/linux/slab.h:973 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2252 sk_alloc+0x3a/0x390 net/core/sock.c:2308 bt_sock_alloc+0x3b/0x340 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1981 [inline] l2cap_sock_create+0x15a/0x300 net/bluetooth/l2cap_sock.c:2019 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:132 __sock_create+0x4e8/0x960 net/socket.c:1691 sock_create net/socket.c:1749 [inline] __sys_socket_create net/socket.c:1786 [inline] __sys_socket+0xd9/0x320 net/socket.c:1833 __do_sys_socket net/socket.c:1847 [inline] __se_sys_socket net/socket.c:1845 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1845 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 27624: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:2706 [inline] slab_free mm/slub.c:6388 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6703 sk_prot_free net/core/sock.c:2291 [inline] __sk_destruct+0x754/0x9e0 net/core/sock.c:2391 l2cap_sock_release+0x1b3/0x250 net/bluetooth/l2cap_sock.c:1493 __sock_release+0xa0/0x1f0 net/socket.c:739 sock_close+0x1c/0x30 net/socket.c:1541 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 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:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:339 [inline] do_syscall_64+0x33d/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880405c4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 512 bytes inside of freed 4096-byte region [ffff8880405c4000, ffff8880405c5000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x405c0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe3c140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe3c140 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4972, tgid 4972 (udevd), ts 1328417137696 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3955 __alloc_frozen_pages_noprof+0x222/0x5b0 mm/page_alloc.c:5394 alloc_slab_page mm/slub.c:3295 [inline] allocate_slab+0x7c/0x5e0 mm/slub.c:3410 new_slab mm/slub.c:3456 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7321 refill_sheaf mm/slub.c:2833 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4699 alloc_from_pcs mm/slub.c:4775 [inline] slab_alloc_node mm/slub.c:4909 [inline] __do_kmalloc_node mm/slub.c:5338 [inline] __kmalloc_noprof+0x543/0x790 mm/slub.c:5364 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776 security_file_open+0x9c/0x200 security/security.c:2739 do_dentry_open+0x4be/0x1420 fs/open.c:924 vfs_open+0x3b/0x350 fs/open.c:1052 do_open fs/namei.c:4694 [inline] path_openat+0x2e64/0x3850 fs/namei.c:4857 do_file_open+0x23e/0x4a0 fs/namei.c:4886 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 page last free pid 23350 tgid 23350 ts 1328107317991 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x1185/0x1270 mm/page_alloc.c:2962 __slab_free+0x252/0x2a0 mm/slub.c:5738 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 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:4608 [inline] slab_alloc_node mm/slub.c:4921 [inline] kmem_cache_alloc_noprof+0x358/0x680 mm/slub.c:4935 vm_area_dup+0x28/0x670 mm/vma_init.c:127 __split_vma+0x1f3/0xbd0 mm/vma.c:531 split_vma mm/vma.c:614 [inline] vma_modify+0x8b7/0x1ec0 mm/vma.c:1736 vma_modify_flags+0x248/0x330 mm/vma.c:1764 mprotect_fixup+0x51a/0xad0 mm/mprotect.c:824 do_mprotect_pkey+0x9d3/0xcd0 mm/mprotect.c:1002 __do_sys_mprotect mm/mprotect.c:1023 [inline] __se_sys_mprotect mm/mprotect.c:1020 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:1020 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880405c4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880405c4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880405c4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880405c4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880405c4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================