Hello, syzbot found the following issue on: HEAD commit: 22b8cc3e78f5 Merge tag 'x86_mm_for_6.4' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1541e08c280000 kernel config: https://syzkaller.appspot.com/x/.config?x=12f36d7d8f9d4b6b dashboard link: https://syzkaller.appspot.com/bug?extid=690b90b14f14f43f4688 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ffa3731397d7/disk-22b8cc3e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/efb7f348dec2/vmlinux-22b8cc3e.xz kernel image: https://storage.googleapis.com/syzbot-assets/955b377bed1f/bzImage-22b8cc3e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+690b90b14f14f43f4688@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in hci_conn_del+0x8b4/0x950 net/bluetooth/hci_conn.c:1114 Read of size 8 at addr ffff8880425669c8 by task syz-executor.0/12291 CPU: 0 PID: 12291 Comm: syz-executor.0 Not tainted 6.3.0-syzkaller-10656-g22b8cc3e78f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 print_report mm/kasan/report.c:462 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:572 hci_conn_del+0x8b4/0x950 net/bluetooth/hci_conn.c:1114 hci_conn_hash_flush+0x1a3/0x270 net/bluetooth/hci_conn.c:2480 hci_dev_close_sync+0x5fb/0x1200 net/bluetooth/hci_sync.c:4941 hci_dev_do_close+0x31/0x70 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1ce/0x580 net/bluetooth/hci_core.c:2703 vhci_release+0x80/0xf0 drivers/bluetooth/hci_vhci.c:669 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad3/0x2960 kernel/exit.c:869 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019 get_signal+0x2315/0x25b0 kernel/signal.c:2874 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2018eb0e91 Code: Unable to access opcode bytes at 0x7f2018eb0e67. RSP: 002b:00007f2019c4a0b0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f2018fabf80 RCX: 00007f2018eb0e91 RDX: 00007f2019c4a0f0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f2018ee7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007ffda36ad2af R14: 00007f2019c4a300 R15: 0000000000022000 </TASK> Allocated by task 16102: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] ____kasan_kmalloc mm/kasan/common.c:333 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:680 [inline] hci_conn_add+0xb8/0x16b0 net/bluetooth/hci_conn.c:986 hci_conn_request_evt+0x89a/0x9c0 net/bluetooth/hci_event.c:3308 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x956/0xfd0 net/bluetooth/hci_event.c:7529 hci_rx_work+0xaeb/0x1340 net/bluetooth/hci_core.c:4062 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Freed by task 12291: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3786 [inline] __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3799 device_release+0xa3/0x240 drivers/base/core.c:2484 kobject_cleanup lib/kobject.c:683 [inline] kobject_release lib/kobject.c:714 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c2/0x4d0 lib/kobject.c:731 put_device+0x1f/0x30 drivers/base/core.c:3733 hci_conn_del+0x1e5/0x950 net/bluetooth/hci_conn.c:1162 hci_conn_unlink+0x2ce/0x460 net/bluetooth/hci_conn.c:1109 hci_conn_hash_flush+0x19b/0x270 net/bluetooth/hci_conn.c:2479 hci_dev_close_sync+0x5fb/0x1200 net/bluetooth/hci_sync.c:4941 hci_dev_do_close+0x31/0x70 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1ce/0x580 net/bluetooth/hci_core.c:2703 vhci_release+0x80/0xf0 drivers/bluetooth/hci_vhci.c:669 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad3/0x2960 kernel/exit.c:869 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019 get_signal+0x2315/0x25b0 kernel/signal.c:2874 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:491 insert_work+0x48/0x350 kernel/workqueue.c:1361 __queue_work+0x625/0x1120 kernel/workqueue.c:1524 __queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1672 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1708 queue_delayed_work include/linux/workqueue.h:519 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1444 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1414 [inline] sco_chan_del+0x1f8/0x4f0 net/bluetooth/sco.c:169 __sco_sock_close+0x178/0x740 net/bluetooth/sco.c:454 sco_sock_close net/bluetooth/sco.c:469 [inline] sco_sock_release+0x81/0x360 net/bluetooth/sco.c:1267 __sock_release+0xcd/0x290 net/socket.c:653 sock_close+0x1c/0x20 net/socket.c:1397 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x25b0 kernel/signal.c:2650 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888042566000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2504 bytes inside of freed 4096-byte region [ffff888042566000, ffff888042567000) The buggy address belongs to the physical page: page:ffffea0001095800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42560 head:ffffea0001095800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000010200 ffff888012442140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 11782, tgid 11777 (syz-executor.1), ts 778445749670, free_ts 774583452034 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1722 prep_new_page mm/page_alloc.c:1729 [inline] get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3493 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4759 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2277 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] __kmem_cache_alloc_node+0x136/0x320 mm/slub.c:3490 __do_kmalloc_node mm/slab_common.c:965 [inline] __kmalloc+0x4e/0x190 mm/slab_common.c:979 kmalloc include/linux/slab.h:563 [inline] tomoyo_realpath_from_path+0xc3/0x600 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x21a/0x570 security/tomoyo/file.c:723 tomoyo_path_mkdir+0x9c/0xe0 security/tomoyo/tomoyo.c:178 security_path_mkdir+0xec/0x160 security/security.c:1695 do_mkdirat+0x14d/0x310 fs/namei.c:4058 __do_sys_mkdirat fs/namei.c:4076 [inline] __se_sys_mkdirat fs/namei.c:4074 [inline] __x64_sys_mkdirat+0x119/0x170 fs/namei.c:4074 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1302 [inline] free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2555 free_unref_page+0x33/0x370 mm/page_alloc.c:2650 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2636 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:711 [inline] slab_alloc_node mm/slub.c:3451 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc_lru+0x20a/0x600 mm/slub.c:3482 alloc_inode_sb include/linux/fs.h:2691 [inline] shmem_alloc_inode+0x27/0x50 mm/shmem.c:3907 alloc_inode+0x61/0x230 fs/inode.c:260 new_inode_pseudo fs/inode.c:1018 [inline] new_inode+0x2b/0x280 fs/inode.c:1046 shmem_get_inode+0x1a3/0xee0 mm/shmem.c:2370 shmem_mknod+0x66/0x220 mm/shmem.c:2942 lookup_open.isra.0+0x105a/0x1400 fs/namei.c:3416 open_last_lookups fs/namei.c:3484 [inline] path_openat+0x975/0x2750 fs/namei.c:3712 do_filp_open+0x1ba/0x410 fs/namei.c:3742 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356 Memory state around the buggy address: ffff888042566880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888042566900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888042566980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888042566a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888042566a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup