[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.123' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 64.807070][ T6870] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 65.040658][ T259] ------------[ cut here ]------------ [ 65.046399][ T259] refcount_t: addition on 0; use-after-free. [ 65.052657][ T259] WARNING: CPU: 1 PID: 259 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 [ 65.061932][ T259] Modules linked in: [ 65.065824][ T259] CPU: 1 PID: 259 Comm: kworker/u4:6 Not tainted 5.9.0-rc6-next-20200922-syzkaller #0 [ 65.075357][ T259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.085426][ T259] Workqueue: qrtr_ns_handler qrtr_ns_worker [ 65.091315][ T259] RIP: 0010:refcount_warn_saturate+0x169/0x1e0 [ 65.097457][ T259] Code: 07 31 ff 89 de e8 07 65 b9 fd 84 db 0f 85 36 ff ff ff e8 da 68 b9 fd 48 c7 c7 60 fa f8 88 c6 05 a8 2e ed 07 01 e8 d2 79 59 04 <0f> 0b e9 17 ff ff ff e8 bb 68 b9 fd 0f b6 1d 8d 2e ed 07 31 ff 89 [ 65.117063][ T259] RSP: 0018:ffffc90001bc79f8 EFLAGS: 00010086 [ 65.123130][ T259] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 65.131088][ T259] RDX: ffff8880a92d02c0 RSI: ffffffff815e0415 RDI: fffff52000378f31 [ 65.139039][ T259] RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae520f8b [ 65.147015][ T259] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a91e5640 [ 65.154980][ T259] R13: ffff8880a5d2cc00 R14: ffff88809e9ad5b0 R15: ffff88809e9ad5b4 [ 65.162938][ T259] FS: 0000000000000000(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 [ 65.171862][ T259] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 65.178429][ T259] CR2: 00007ffd2a9d8780 CR3: 0000000094b26000 CR4: 00000000001506e0 [ 65.186396][ T259] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 65.194369][ T259] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 65.202332][ T259] Call Trace: [ 65.205628][ T259] qrtr_recvmsg+0x845/0x970 [ 65.210116][ T259] ? qrtr_node_enqueue+0x1250/0x1250 [ 65.216169][ T259] ? mark_held_locks+0x9f/0xe0 [ 65.220922][ T259] ? lock_is_held_type+0xbb/0xf0 [ 65.225844][ T259] ? bpf_lsm_socket_recvmsg+0x5/0x10 [ 65.231120][ T259] ? security_socket_recvmsg+0x8f/0xc0 [ 65.236560][ T259] ? qrtr_node_enqueue+0x1250/0x1250 [ 65.241829][ T259] kernel_recvmsg+0x110/0x160 [ 65.246490][ T259] qrtr_ns_worker+0x15a/0x1430 [ 65.251266][ T259] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 65.257252][ T259] ? ctrl_cmd_del_client+0x730/0x730 [ 65.262535][ T259] ? lock_acquire+0x1f2/0xaa0 [ 65.267200][ T259] ? process_one_work+0x854/0x15a0 [ 65.272304][ T259] ? lock_is_held_type+0xbb/0xf0 [ 65.277247][ T259] process_one_work+0x933/0x15a0 [ 65.282252][ T259] ? pwq_dec_nr_in_flight+0x320/0x320 [ 65.287648][ T259] ? rwlock_bug.part.0+0x90/0x90 [ 65.292571][ T259] worker_thread+0x64c/0x1120 [ 65.297243][ T259] ? process_one_work+0x15a0/0x15a0 [ 65.302454][ T259] kthread+0x3af/0x4a0 [ 65.306507][ T259] ? __kthread_bind_mask+0xc0/0xc0 [ 65.311607][ T259] ret_from_fork+0x1f/0x30 [ 65.316011][ T259] Kernel panic - not syncing: panic_on_warn set ... [ 65.322593][ T259] CPU: 1 PID: 259 Comm: kworker/u4:6 Not tainted 5.9.0-rc6-next-20200922-syzkaller #0 [ 65.332108][ T259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.342154][ T259] Workqueue: qrtr_ns_handler qrtr_ns_worker [ 65.348126][ T259] Call Trace: [ 65.351410][ T259] dump_stack+0x198/0x1fb [ 65.355722][ T259] panic+0x382/0x7fb [ 65.359596][ T259] ? __warn_printk+0xf3/0xf3 [ 65.364174][ T259] ? __warn.cold+0x1d/0xbb [ 65.368586][ T259] ? __warn.cold+0x14/0xbb [ 65.372986][ T259] ? refcount_warn_saturate+0x169/0x1e0 [ 65.378512][ T259] __warn.cold+0x38/0xbb [ 65.382735][ T259] ? refcount_warn_saturate+0x169/0x1e0 [ 65.388270][ T259] report_bug+0x1bd/0x210 [ 65.392597][ T259] handle_bug+0x38/0x90 [ 65.396745][ T259] exc_invalid_op+0x14/0x40 [ 65.401240][ T259] asm_exc_invalid_op+0x12/0x20 [ 65.406099][ T259] RIP: 0010:refcount_warn_saturate+0x169/0x1e0 [ 65.412239][ T259] Code: 07 31 ff 89 de e8 07 65 b9 fd 84 db 0f 85 36 ff ff ff e8 da 68 b9 fd 48 c7 c7 60 fa f8 88 c6 05 a8 2e ed 07 01 e8 d2 79 59 04 <0f> 0b e9 17 ff ff ff e8 bb 68 b9 fd 0f b6 1d 8d 2e ed 07 31 ff 89 [ 65.431837][ T259] RSP: 0018:ffffc90001bc79f8 EFLAGS: 00010086 [ 65.437890][ T259] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 65.445847][ T259] RDX: ffff8880a92d02c0 RSI: ffffffff815e0415 RDI: fffff52000378f31 [ 65.453813][ T259] RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae520f8b [ 65.461785][ T259] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a91e5640 [ 65.469739][ T259] R13: ffff8880a5d2cc00 R14: ffff88809e9ad5b0 R15: ffff88809e9ad5b4 [ 65.477719][ T259] ? vprintk_func+0x95/0x1e0 [ 65.482311][ T259] ? refcount_warn_saturate+0x169/0x1e0 [ 65.487850][ T259] qrtr_recvmsg+0x845/0x970 [ 65.492345][ T259] ? qrtr_node_enqueue+0x1250/0x1250 [ 65.497621][ T259] ? mark_held_locks+0x9f/0xe0 [ 65.502385][ T259] ? lock_is_held_type+0xbb/0xf0 [ 65.507312][ T259] ? bpf_lsm_socket_recvmsg+0x5/0x10 [ 65.512577][ T259] ? security_socket_recvmsg+0x8f/0xc0 [ 65.518032][ T259] ? qrtr_node_enqueue+0x1250/0x1250 [ 65.523320][ T259] kernel_recvmsg+0x110/0x160 [ 65.527981][ T259] qrtr_ns_worker+0x15a/0x1430 [ 65.532735][ T259] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 65.538708][ T259] ? ctrl_cmd_del_client+0x730/0x730 [ 65.543987][ T259] ? lock_acquire+0x1f2/0xaa0 [ 65.548658][ T259] ? process_one_work+0x854/0x15a0 [ 65.553784][ T259] ? lock_is_held_type+0xbb/0xf0 [ 65.558712][ T259] process_one_work+0x933/0x15a0 [ 65.563650][ T259] ? pwq_dec_nr_in_flight+0x320/0x320 [ 65.569070][ T259] ? rwlock_bug.part.0+0x90/0x90 [ 65.574001][ T259] worker_thread+0x64c/0x1120 [ 65.578706][ T259] ? process_one_work+0x15a0/0x15a0 [ 65.583889][ T259] kthread+0x3af/0x4a0 [ 65.587951][ T259] ? __kthread_bind_mask+0xc0/0xc0 [ 65.593057][ T259] ret_from_fork+0x1f/0x30 [ 66.667113][ T259] Shutting down cpus with NMI [ 66.673005][ T259] Kernel Offset: disabled [ 66.677417][ T259] Rebooting in 86400 seconds..