Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.53' (ECDSA) to the list of known hosts. syzkaller login: [ 38.586371] audit: type=1400 audit(1596825988.801:8): avc: denied { execmem } for pid=6478 comm="syz-executor510" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 38.599401] IPVS: ftp: loaded support on port[0] = 21 executing program [ 39.755249] ================================================================== [ 39.763562] BUG: KASAN: use-after-free in hci_chan_del+0x13e/0x180 [ 39.769896] Read of size 8 at addr ffff88809af25a98 by task syz-executor510/6479 [ 39.777422] [ 39.779056] CPU: 0 PID: 6479 Comm: syz-executor510 Not tainted 4.19.138-syzkaller #0 [ 39.786927] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.796261] Call Trace: [ 39.798883] dump_stack+0x1fc/0x2fe [ 39.802550] ? l2cap_conn_del+0x6b0/0x6b0 [ 39.806683] print_address_description.cold+0x54/0x219 [ 39.811944] kasan_report_error.cold+0x8a/0x1c7 [ 39.816609] ? hci_chan_del+0x13e/0x180 [ 39.820565] __asan_report_load8_noabort+0x88/0x90 [ 39.825483] ? hci_chan_del+0x13e/0x180 [ 39.829464] hci_chan_del+0x13e/0x180 [ 39.833270] l2cap_conn_del+0x44f/0x6b0 [ 39.837226] ? l2cap_conn_del+0x6b0/0x6b0 [ 39.841380] l2cap_disconn_cfm+0x85/0xa0 [ 39.845421] hci_conn_hash_flush+0x114/0x220 [ 39.849813] hci_dev_do_close+0x624/0xe70 [ 39.853945] ? hci_dev_open+0x2a0/0x2a0 [ 39.857918] ? hci_unregister_dev+0x62/0x7f0 [ 39.862317] hci_unregister_dev+0x17c/0x7f0 [ 39.866627] ? vhci_close_dev+0x50/0x50 [ 39.870597] vhci_release+0x70/0xe0 [ 39.874318] __fput+0x2ce/0x890 [ 39.877598] task_work_run+0x148/0x1c0 [ 39.881470] do_exit+0xbb2/0x2b70 [ 39.884908] ? mm_update_next_owner+0x650/0x650 [ 39.889555] ? vfs_write+0x393/0x540 [ 39.893248] ? ksys_write+0x1c8/0x2a0 [ 39.897031] do_group_exit+0x125/0x310 [ 39.900901] __x64_sys_exit_group+0x3a/0x50 [ 39.905202] do_syscall_64+0xf9/0x620 [ 39.908987] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 39.914157] RIP: 0033:0x445228 [ 39.917351] Code: Bad RIP value. [ 39.920694] RSP: 002b:00007ffe24ee7488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 39.928380] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000445228 [ 39.935643] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 39.943154] RBP: 00000000004cd010 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 39.950404] R10: 00000000000000ff R11: 0000000000000246 R12: 0000000000000001 [ 39.957677] R13: 00000000006e0240 R14: 0000000000000000 R15: 0000000000000000 [ 39.964931] [ 39.966536] Allocated by task 6504: [ 39.970147] kmem_cache_alloc_trace+0x12f/0x380 [ 39.974796] hci_chan_create+0x8e/0x310 [ 39.978764] l2cap_conn_add.part.0+0x18/0xc40 [ 39.983237] l2cap_connect_cfm+0x236/0xe70 [ 39.987451] le_conn_complete_evt+0x111b/0x1730 [ 39.992101] hci_le_meta_evt+0x32c/0x3a50 [ 39.996227] hci_event_packet+0x1a29/0x858f [ 40.000544] hci_rx_work+0x46b/0xa90 [ 40.004236] process_one_work+0x864/0x1570 [ 40.008449] worker_thread+0x64c/0x1130 [ 40.012416] kthread+0x30b/0x410 [ 40.015763] ret_from_fork+0x24/0x30 [ 40.019450] [ 40.021052] Freed by task 1226: [ 40.024314] kfree+0xcc/0x210 [ 40.027399] hci_event_packet+0xf52/0x858f [ 40.031614] hci_rx_work+0x46b/0xa90 [ 40.035305] process_one_work+0x864/0x1570 [ 40.039518] worker_thread+0x64c/0x1130 [ 40.043488] kthread+0x30b/0x410 [ 40.046835] ret_from_fork+0x24/0x30 [ 40.050520] [ 40.052123] The buggy address belongs to the object at ffff88809af25a80 [ 40.052123] which belongs to the cache kmalloc-128 of size 128 [ 40.064763] The buggy address is located 24 bytes inside of [ 40.064763] 128-byte region [ffff88809af25a80, ffff88809af25b00) [ 40.076543] The buggy address belongs to the page: [ 40.081454] page:ffffea00026bc940 count:1 mapcount:0 mapping:ffff88812c39c640 index:0x0 [ 40.089574] flags: 0xfffe0000000100(slab) [ 40.093705] raw: 00fffe0000000100 ffffea00026b3e48 ffffea000269e648 ffff88812c39c640 [ 40.101566] raw: 0000000000000000 ffff88809af25000 0000000100000015 0000000000000000 [ 40.109421] page dumped because: kasan: bad access detected [ 40.115104] [ 40.116823] Memory state around the buggy address: [ 40.121731] ffff88809af25980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 40.129075] ffff88809af25a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 40.136413] >ffff88809af25a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.143773] ^ [ 40.147899] ffff88809af25b00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 [ 40.155235] ffff88809af25b80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc [ 40.162584] ================================================================== [ 40.170190] Disabling lock debugging due to kernel taint [ 40.176436] Kernel panic - not syncing: panic_on_warn set ... [ 40.176436] [ 40.183812] CPU: 0 PID: 6479 Comm: syz-executor510 Tainted: G B 4.19.138-syzkaller #0 [ 40.193084] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.202427] Call Trace: [ 40.205002] dump_stack+0x1fc/0x2fe [ 40.208611] ? l2cap_conn_del+0x6b0/0x6b0 [ 40.212738] panic+0x26a/0x50e [ 40.215927] ? __warn_printk+0xf3/0xf3 [ 40.219800] ? l2cap_conn_del+0x6b0/0x6b0 [ 40.223929] ? preempt_schedule_common+0x45/0xc0 [ 40.228666] ? ___preempt_schedule+0x16/0x18 [ 40.233059] ? trace_hardirqs_on+0x55/0x210 [ 40.237360] ? l2cap_conn_del+0x6b0/0x6b0 [ 40.241487] kasan_end_report+0x43/0x49 [ 40.245446] kasan_report_error.cold+0xa7/0x1c7 [ 40.250096] ? hci_chan_del+0x13e/0x180 [ 40.254056] __asan_report_load8_noabort+0x88/0x90 [ 40.258976] ? hci_chan_del+0x13e/0x180 [ 40.262929] hci_chan_del+0x13e/0x180 [ 40.266712] l2cap_conn_del+0x44f/0x6b0 [ 40.270669] ? l2cap_conn_del+0x6b0/0x6b0 [ 40.274796] l2cap_disconn_cfm+0x85/0xa0 [ 40.278838] hci_conn_hash_flush+0x114/0x220 [ 40.283231] hci_dev_do_close+0x624/0xe70 [ 40.287378] ? hci_dev_open+0x2a0/0x2a0 [ 40.291336] ? hci_unregister_dev+0x62/0x7f0 [ 40.295732] hci_unregister_dev+0x17c/0x7f0 [ 40.300038] ? vhci_close_dev+0x50/0x50 [ 40.303995] vhci_release+0x70/0xe0 [ 40.307603] __fput+0x2ce/0x890 [ 40.310867] task_work_run+0x148/0x1c0 [ 40.314739] do_exit+0xbb2/0x2b70 [ 40.318175] ? mm_update_next_owner+0x650/0x650 [ 40.322825] ? vfs_write+0x393/0x540 [ 40.326522] ? ksys_write+0x1c8/0x2a0 [ 40.330312] do_group_exit+0x125/0x310 [ 40.334181] __x64_sys_exit_group+0x3a/0x50 [ 40.338486] do_syscall_64+0xf9/0x620 [ 40.342285] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.348413] RIP: 0033:0x445228 [ 40.351597] Code: Bad RIP value. [ 40.354939] RSP: 002b:00007ffe24ee7488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 40.362628] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000445228 [ 40.369888] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 40.377136] RBP: 00000000004cd010 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 40.384384] R10: 00000000000000ff R11: 0000000000000246 R12: 0000000000000001 [ 40.391634] R13: 00000000006e0240 R14: 0000000000000000 R15: 0000000000000000 [ 40.400074] Kernel Offset: disabled [ 40.403691] Rebooting in 86400 seconds..