[ 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 '10.128.15.207' (ECDSA) to the list of known hosts. syzkaller login: [ 40.369651] IPVS: ftp: loaded support on port[0] = 21 [ 40.380930] IPVS: ftp: loaded support on port[0] = 21 [ 40.381029] IPVS: ftp: loaded support on port[0] = 21 [ 40.396140] IPVS: ftp: loaded support on port[0] = 21 [ 40.409259] IPVS: ftp: loaded support on port[0] = 21 [ 40.416723] 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 [ 40.887976] ================================================================== [ 40.895510] BUG: KASAN: use-after-free in ex_handler_refcount+0x18f/0x1c0 [ 40.902440] Write of size 4 at addr ffff88808968ad58 by task kworker/1:0/19 [ 40.909531] [ 40.911162] CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.19.115-syzkaller #0 [ 40.918519] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.927880] Workqueue: events do_enable_set [ 40.932201] Call Trace: [ 40.934791] dump_stack+0x188/0x20d executing program executing program [ 40.938427] ? ex_handler_refcount+0x18f/0x1c0 [ 40.943021] print_address_description.cold+0x7c/0x212 [ 40.948310] ? ex_handler_refcount+0x18f/0x1c0 [ 40.952902] kasan_report.cold+0x88/0x2b9 [ 40.957065] ex_handler_refcount+0x18f/0x1c0 [ 40.961485] ? ex_handler_clear_fs+0xb0/0xb0 [ 40.965898] fixup_exception+0x8a/0xc3 [ 40.969796] do_trap+0x72/0x230 [ 40.973078] ? do_error_trap+0x212/0x310 [ 40.977161] do_error_trap+0x15d/0x310 [ 40.981052] ? math_error+0x310/0x310 executing program executing program executing program executing program [ 40.984859] ? csum_partial_copy_generic+0x6682/0x8652 [ 40.990153] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.995007] invalid_op+0x14/0x20 [ 40.998467] RIP: 0010:csum_partial_copy_generic+0x6682/0x8652 [ 41.004353] Code: 8d 8c 24 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 4d 00 0f 0b 48 8d 4b 18 <0f> 0b 48 8d 8b b8 02 00 00 0f 0b 49 8d 8c 24 b8 02 00 00 0f 0b 48 [ 41.023261] RSP: 0018:ffff8880a9f27c50 EFLAGS: 00010297 [ 41.028631] RAX: ffff8880a9f1a500 RBX: ffff88808968ad40 RCX: ffff88808968ad58 executing program executing program [ 41.035908] RDX: 0000000000000000 RSI: ffffffff8665b56a RDI: ffff88808968ad40 [ 41.043181] RBP: ffff88808968ad58 R08: ffff8880a9f1a500 R09: ffffed1015ce4733 [ 41.050457] R10: ffffed1015ce4732 R11: ffff8880ae723993 R12: 0000000000000080 [ 41.057731] R13: ffff8880a406e200 R14: ffff8880a9e16200 R15: ffff8880ae72ba80 [ 41.065022] ? l2cap_chan_put+0xa/0x40 [ 41.068927] do_enable_set+0x4d1/0x8d0 [ 41.072822] ? process_one_work+0x82c/0x1640 [ 41.077254] ? lowpan_control_write+0x480/0x480 [ 41.081944] ? __lock_is_held+0xad/0x140 [ 41.086033] process_one_work+0x91f/0x1640 [ 41.090285] ? pwq_dec_nr_in_flight+0x310/0x310 [ 41.094970] worker_thread+0x96/0xe20 [ 41.098785] ? process_one_work+0x1640/0x1640 [ 41.103288] kthread+0x34a/0x420 [ 41.106659] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 41.112203] ret_from_fork+0x24/0x30 [ 41.115925] [ 41.117555] Allocated by task 19: [ 41.121013] kasan_kmalloc+0xbf/0xe0 [ 41.124851] kmem_cache_alloc_trace+0x14d/0x7a0 [ 41.129526] l2cap_chan_create+0x40/0x380 [ 41.133673] chan_create+0xc/0xd0 [ 41.137126] do_enable_set+0x507/0x8d0 [ 41.141015] process_one_work+0x91f/0x1640 [ 41.145256] worker_thread+0x96/0xe20 [ 41.149056] kthread+0x34a/0x420 [ 41.152425] ret_from_fork+0x24/0x30 [ 41.156133] [ 41.157759] Freed by task 6119: [ 41.161055] __kasan_slab_free+0xf7/0x140 [ 41.165218] kfree+0xce/0x220 [ 41.168326] l2cap_chan_put+0x35/0x40 [ 41.172127] do_enable_set+0x4d1/0x8d0 [ 41.176016] process_one_work+0x91f/0x1640 [ 41.180251] worker_thread+0x96/0xe20 [ 41.184052] kthread+0x34a/0x420 [ 41.187421] ret_from_fork+0x24/0x30 [ 41.191127] [ 41.192757] The buggy address belongs to the object at ffff88808968ad40 [ 41.192757] which belongs to the cache kmalloc-2048 of size 2048 [ 41.205596] The buggy address is located 24 bytes inside of [ 41.205596] 2048-byte region [ffff88808968ad40, ffff88808968b540) [ 41.217477] The buggy address belongs to the page: [ 41.222419] page:ffffea000225a280 count:1 mapcount:0 mapping:ffff88812c3dcc40 index:0x0 compound_mapcount: 0 [ 41.232390] flags: 0xfffe0000008100(slab|head) [ 41.236980] raw: 00fffe0000008100 ffffea0002913008 ffffea000225ca08 ffff88812c3dcc40 [ 41.244867] raw: 0000000000000000 ffff88808968a4c0 0000000100000003 0000000000000000 [ 41.252751] page dumped because: kasan: bad access detected [ 41.258457] [ 41.260080] Memory state around the buggy address: [ 41.265007] ffff88808968ac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 41.272367] ffff88808968ac80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 41.279730] >ffff88808968ad00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb 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 [ 41.287092] ^ [ 41.293329] ffff88808968ad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.300696] ffff88808968ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 41.308048] ================================================================== [ 41.315391] Disabling lock debugging due to kernel taint 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 [ 41.910910] Kernel panic - not syncing: panic_on_warn set ... [ 41.910910] [ 41.918329] CPU: 1 PID: 19 Comm: kworker/1:0 Tainted: G B 4.19.115-syzkaller #0 [ 41.927079] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.936438] Workqueue: events do_enable_set [ 41.940755] Call Trace: [ 41.943344] dump_stack+0x188/0x20d [ 41.946981] panic+0x26a/0x50e [ 41.950326] ? __warn_printk+0xf3/0xf3 [ 41.954220] ? preempt_schedule_common+0x4a/0xc0 [ 41.958985] ? ex_handler_refcount+0x18f/0x1c0 [ 41.963567] ? ___preempt_schedule+0x16/0x18 [ 41.967974] ? trace_hardirqs_on+0x55/0x210 [ 41.972299] ? ex_handler_refcount+0x18f/0x1c0 [ 41.976888] kasan_end_report+0x43/0x49 [ 41.980872] kasan_report.cold+0xa4/0x2b9 [ 41.985026] ex_handler_refcount+0x18f/0x1c0 [ 41.989442] ? ex_handler_clear_fs+0xb0/0xb0 [ 41.993873] fixup_exception+0x8a/0xc3 [ 41.997765] do_trap+0x72/0x230 [ 42.001050] ? do_error_trap+0x212/0x310 [ 42.005985] do_error_trap+0x15d/0x310 [ 42.009875] ? math_error+0x310/0x310 [ 42.013677] ? csum_partial_copy_generic+0x6682/0x8652 [ 42.018964] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.023815] invalid_op+0x14/0x20 [ 42.027302] RIP: 0010:csum_partial_copy_generic+0x6682/0x8652 [ 42.033183] Code: 8d 8c 24 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 4d 00 0f 0b 48 8d 4b 18 <0f> 0b 48 8d 8b b8 02 00 00 0f 0b 49 8d 8c 24 b8 02 00 00 0f 0b 48 [ 42.052081] RSP: 0018:ffff8880a9f27c50 EFLAGS: 00010297 [ 42.057443] RAX: ffff8880a9f1a500 RBX: ffff88808968ad40 RCX: ffff88808968ad58 [ 42.064715] RDX: 0000000000000000 RSI: ffffffff8665b56a RDI: ffff88808968ad40 [ 42.071990] RBP: ffff88808968ad58 R08: ffff8880a9f1a500 R09: ffffed1015ce4733 [ 42.079261] R10: ffffed1015ce4732 R11: ffff8880ae723993 R12: 0000000000000080 [ 42.086534] R13: ffff8880a406e200 R14: ffff8880a9e16200 R15: ffff8880ae72ba80 [ 42.093916] ? l2cap_chan_put+0xa/0x40 [ 42.097810] do_enable_set+0x4d1/0x8d0 [ 42.101699] ? process_one_work+0x82c/0x1640 [ 42.106112] ? lowpan_control_write+0x480/0x480 [ 42.110788] ? __lock_is_held+0xad/0x140 [ 42.114857] process_one_work+0x91f/0x1640 [ 42.119100] ? pwq_dec_nr_in_flight+0x310/0x310 [ 42.123778] worker_thread+0x96/0xe20 [ 42.127585] ? process_one_work+0x1640/0x1640 [ 42.132085] kthread+0x34a/0x420 [ 42.135456] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 42.141007] ret_from_fork+0x24/0x30 [ 42.145860] Kernel Offset: disabled [ 42.149482] Rebooting in 86400 seconds..