audit: type=1400 audit(1596678947.002:8): avc: denied { execmem } for pid=6446 comm="syz-executor927" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 IPVS: ftp: loaded support on port[0] = 21 ================================================================== BUG: KASAN: use-after-free in hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666 Read of size 8 at addr ffff8880a1275918 by task syz-executor927/6447 CPU: 1 PID: 6447 Comm: syz-executor927 Not tainted 4.19.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666 l2cap_conn_del+0x44f/0x6b0 net/bluetooth/l2cap_core.c:1736 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline] l2cap_disconn_cfm+0x85/0xa0 net/bluetooth/l2cap_core.c:7428 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline] hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1495 hci_dev_do_close+0x624/0xe70 net/bluetooth/hci_core.c:1666 hci_unregister_dev+0x17c/0x7f0 net/bluetooth/hci_core.c:3271 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbb2/0x2b70 kernel/exit.c:887 do_group_exit+0x125/0x310 kernel/exit.c:990 __do_sys_exit_group kernel/exit.c:1001 [inline] __se_sys_exit_group kernel/exit.c:999 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:999 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4450e8 Code: Bad RIP value. RSP: 002b:00007ffcfdb62768 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000004450e8 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00000000004cced0 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006e0200 R14: 0000000001030850 R15: 0000000000000001 Allocated by task 6474: kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] hci_chan_create+0x8e/0x310 net/bluetooth/hci_conn.c:1651 l2cap_conn_add.part.0+0x18/0xc40 net/bluetooth/l2cap_core.c:7056 l2cap_conn_add net/bluetooth/l2cap_core.c:7415 [inline] l2cap_connect_cfm+0x236/0xe70 net/bluetooth/l2cap_core.c:7373 hci_connect_cfm include/net/bluetooth/hci_core.h:1246 [inline] le_conn_complete_evt+0x111b/0x1730 net/bluetooth/hci_event.c:4931 hci_le_enh_conn_complete_evt net/bluetooth/hci_event.c:4973 [inline] hci_le_meta_evt+0x32c/0x3a50 net/bluetooth/hci_event.c:5661 hci_event_packet+0x1a29/0x858f net/bluetooth/hci_event.c:5897 hci_rx_work+0x46b/0xa90 net/bluetooth/hci_core.c:4359 process_one_work+0x864/0x1570 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Freed by task 1226: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4758 [inline] hci_event_packet+0xf52/0x858f net/bluetooth/hci_event.c:5918 hci_rx_work+0x46b/0xa90 net/bluetooth/hci_core.c:4359 process_one_work+0x864/0x1570 kernel/workqueue.c:2155 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff8880a1275900 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of 128-byte region [ffff8880a1275900, ffff8880a1275980) The buggy address belongs to the page: page:ffffea0002849d40 count:1 mapcount:0 mapping:ffff88812c39c640 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea00026efc48 ffffea0002793888 ffff88812c39c640 raw: 0000000000000000 ffff8880a1275000 0000000100000015 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1275800: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff8880a1275880: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff8880a1275900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a1275980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8880a1275a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================