[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.236' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 35.401658] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.452650] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.501732] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.560179] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.610313] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.660823] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program executing program [ 35.711657] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. [ 35.751012] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program [ 35.790054] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. executing program executing program [ 35.831735] netlink: 4 bytes leftover after parsing attributes in process `syz-executor123'. 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 [ 37.400949] ================================================================== [ 37.408423] BUG: KASAN: use-after-free in ex_handler_refcount+0x18f/0x1c0 [ 37.415358] Write of size 4 at addr ffff8880a9935118 by task systemd-udevd/8371 [ 37.422780] [ 37.424392] CPU: 0 PID: 8371 Comm: systemd-udevd Not tainted 4.19.211-syzkaller #0 [ 37.432075] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.441406] Call Trace: [ 37.443977] dump_stack+0x1fc/0x2ef [ 37.447589] print_address_description.cold+0x54/0x219 [ 37.452848] kasan_report_error.cold+0x8a/0x1b9 [ 37.457533] ? ex_handler_refcount+0x18f/0x1c0 [ 37.462104] __asan_report_store4_noabort+0x88/0x90 [ 37.467116] ? ex_handler_refcount+0x18f/0x1c0 [ 37.471688] ex_handler_refcount+0x18f/0x1c0 [ 37.476082] ? ex_handler_clear_fs+0xb0/0xb0 [ 37.480481] fixup_exception+0x8a/0xd0 [ 37.484361] do_trap+0x61/0x250 [ 37.487644] do_error_trap+0x15d/0x310 [ 37.491543] ? math_error+0x310/0x310 [ 37.495425] ? __noinstr_text_end+0x243b/0x7813 [ 37.500087] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.504916] invalid_op+0x14/0x20 [ 37.508359] RIP: 0010:__noinstr_text_end+0x243b/0x7813 [ 37.513665] Code: 0f 0b 48 8d 4b 50 0f 0b 48 8d 4b 08 0f 0b 48 8d 4d 08 0f 0b 48 8d 8d 08 02 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 0b 0f 0b 48 8d 0b <0f> 0b 48 8d 4d 00 0f 0b 49 8d 0c 24 0f 0b 48 8d 8b c0 00 00 00 0f [ 37.532691] RSP: 0018:ffff8880939c7cd8 EFLAGS: 00010296 [ 37.538036] RAX: 0000000000000000 RBX: ffff8880a9935118 RCX: ffff8880a9935118 [ 37.545296] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 37.552557] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7985 [ 37.559816] R10: ffffffff8a5bcc2b R11: 0000000000000000 R12: ffffffff8a5bcc20 [ 37.567065] R13: 0000000000000000 R14: 1ffff1101149fe4d R15: dffffc0000000000 [ 37.574353] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 37.579444] nbd_release+0x108/0x170 [ 37.583159] ? nbd_queue_rq+0xe60/0xe60 [ 37.587113] __blkdev_put+0x636/0x870 [ 37.590895] ? fsync_bdev+0xc0/0xc0 [ 37.594501] ? locks_remove_file+0x2cd/0x450 [ 37.598893] ? blkdev_put+0x85/0x520 [ 37.602591] ? blkdev_put+0x520/0x520 [ 37.606368] blkdev_close+0x86/0xb0 [ 37.609975] __fput+0x2ce/0x890 [ 37.613240] task_work_run+0x148/0x1c0 [ 37.617114] exit_to_usermode_loop+0x251/0x2a0 [ 37.621675] do_syscall_64+0x538/0x620 [ 37.625555] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.630724] RIP: 0033:0x7f83459c9270 [ 37.634423] Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 [ 37.653312] RSP: 002b:00007fff08015078 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 37.661023] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f83459c9270 [ 37.668290] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 37.675543] RBP: 00007f8346883710 R08: 0000559708bc9870 R09: 0000000000000018 [ 37.682796] R10: 0000559708bda8f8 R11: 0000000000000246 R12: 0000000000000000 [ 37.690051] R13: 0000559708bd76e0 R14: 0000000000000003 R15: 000000000000000e [ 37.697309] [ 37.698936] Allocated by task 8345: [ 37.702561] kmem_cache_alloc_trace+0x12f/0x380 [ 37.707211] nbd_dev_add+0x44/0x890 [ 37.710820] nbd_genl_connect+0x4cc/0x1630 [ 37.715039] genl_family_rcv_msg+0x642/0xc40 [ 37.719426] genl_rcv_msg+0xbf/0x160 [ 37.723137] netlink_rcv_skb+0x160/0x440 [ 37.727177] genl_rcv+0x24/0x40 [ 37.730444] netlink_unicast+0x4d5/0x690 [ 37.734482] netlink_sendmsg+0x6c3/0xc50 [ 37.738524] sock_sendmsg+0xc3/0x120 [ 37.742233] ___sys_sendmsg+0x7bb/0x8e0 [ 37.746184] __x64_sys_sendmsg+0x132/0x220 [ 37.750396] do_syscall_64+0xf9/0x620 [ 37.754177] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.759343] [ 37.760950] Freed by task 8331: [ 37.764210] kfree+0xcc/0x210 [ 37.767295] nbd_put.part.0+0xfe/0x140 [ 37.771167] nbd_genl_connect+0x120e/0x1630 [ 37.775467] genl_family_rcv_msg+0x642/0xc40 [ 37.779851] genl_rcv_msg+0xbf/0x160 [ 37.783771] netlink_rcv_skb+0x160/0x440 [ 37.787811] genl_rcv+0x24/0x40 [ 37.791075] netlink_unicast+0x4d5/0x690 [ 37.795126] netlink_sendmsg+0x6c3/0xc50 [ 37.799280] sock_sendmsg+0xc3/0x120 [ 37.802999] ___sys_sendmsg+0x7bb/0x8e0 [ 37.806955] __x64_sys_sendmsg+0x132/0x220 [ 37.811170] do_syscall_64+0xf9/0x620 [ 37.814950] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.820116] [ 37.821726] The buggy address belongs to the object at ffff8880a9935040 [ 37.821726] which belongs to the cache kmalloc-512 of size 512 [ 37.834366] The buggy address is located 216 bytes inside of [ 37.834366] 512-byte region [ffff8880a9935040, ffff8880a9935240) [ 37.846215] The buggy address belongs to the page: [ 37.851138] page:ffffea0002a64d40 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 37.859261] flags: 0xfff00000000100(slab) [ 37.863391] raw: 00fff00000000100 ffffea0002921dc8 ffffea0002a622c8 ffff88813bff0940 [ 37.871250] raw: 0000000000000000 ffff8880a9935040 0000000100000006 0000000000000000 [ 37.879104] page dumped because: kasan: bad access detected [ 37.884796] [ 37.886402] Memory state around the buggy address: [ 37.891316] ffff8880a9935000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 37.898662] ffff8880a9935080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 37.906005] >ffff8880a9935100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 37.913356] ^ [ 37.917483] ffff8880a9935180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 37.924857] ffff8880a9935200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 37.932189] ================================================================== [ 37.939531] Disabling lock debugging due to kernel taint executing program [ 37.948814] Kernel panic - not syncing: panic_on_warn set ... [ 37.948814] [ 37.956196] CPU: 1 PID: 8371 Comm: systemd-udevd Tainted: G B 4.19.211-syzkaller #0 [ 37.965284] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.974629] Call Trace: [ 37.977210] dump_stack+0x1fc/0x2ef [ 37.980828] panic+0x26a/0x50e [ 37.984025] ? __warn_printk+0xf3/0xf3 [ 37.987925] ? preempt_schedule_common+0x45/0xc0 [ 37.992662] ? ___preempt_schedule+0x16/0x18 [ 37.997048] ? trace_hardirqs_on+0x55/0x210 [ 38.001352] kasan_end_report+0x43/0x49 [ 38.005304] kasan_report_error.cold+0xa7/0x1b9 [ 38.009950] ? ex_handler_refcount+0x18f/0x1c0 [ 38.014510] __asan_report_store4_noabort+0x88/0x90 [ 38.019505] ? ex_handler_refcount+0x18f/0x1c0 [ 38.024064] ex_handler_refcount+0x18f/0x1c0 [ 38.028447] ? ex_handler_clear_fs+0xb0/0xb0 [ 38.032838] fixup_exception+0x8a/0xd0 [ 38.036722] do_trap+0x61/0x250 [ 38.039979] do_error_trap+0x15d/0x310 [ 38.043874] ? math_error+0x310/0x310 [ 38.047650] ? __noinstr_text_end+0x243b/0x7813 [ 38.052297] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.057116] invalid_op+0x14/0x20 [ 38.060548] RIP: 0010:__noinstr_text_end+0x243b/0x7813 [ 38.065800] Code: 0f 0b 48 8d 4b 50 0f 0b 48 8d 4b 08 0f 0b 48 8d 4d 08 0f 0b 48 8d 8d 08 02 00 00 0f 0b 48 8d 0b 0f 0b 48 8d 0b 0f 0b 48 8d 0b <0f> 0b 48 8d 4d 00 0f 0b 49 8d 0c 24 0f 0b 48 8d 8b c0 00 00 00 0f [ 38.084681] RSP: 0018:ffff8880939c7cd8 EFLAGS: 00010296 [ 38.090023] RAX: 0000000000000000 RBX: ffff8880a9935118 RCX: ffff8880a9935118 [ 38.097278] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 38.104526] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7985 [ 38.111769] R10: ffffffff8a5bcc2b R11: 0000000000000000 R12: ffffffff8a5bcc20 [ 38.119013] R13: 0000000000000000 R14: 1ffff1101149fe4d R15: dffffc0000000000 [ 38.126270] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 38.131350] nbd_release+0x108/0x170 [ 38.135040] ? nbd_queue_rq+0xe60/0xe60 [ 38.138996] __blkdev_put+0x636/0x870 [ 38.142774] ? fsync_bdev+0xc0/0xc0 [ 38.146382] ? locks_remove_file+0x2cd/0x450 [ 38.150767] ? blkdev_put+0x85/0x520 [ 38.154458] ? blkdev_put+0x520/0x520 [ 38.158231] blkdev_close+0x86/0xb0 [ 38.161853] __fput+0x2ce/0x890 [ 38.165112] task_work_run+0x148/0x1c0 [ 38.168978] exit_to_usermode_loop+0x251/0x2a0 [ 38.173539] do_syscall_64+0x538/0x620 [ 38.177407] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.182577] RIP: 0033:0x7f83459c9270 [ 38.186265] Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 [ 38.205146] RSP: 002b:00007fff08015078 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 38.212828] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f83459c9270 [ 38.220077] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 38.227323] RBP: 00007f8346883710 R08: 0000559708bc9870 R09: 0000000000000018 [ 38.234570] R10: 0000559708bda8f8 R11: 0000000000000246 R12: 0000000000000000 [ 38.241847] R13: 0000559708bd76e0 R14: 0000000000000003 R15: 000000000000000e [ 38.251812] Kernel Offset: disabled [ 38.255420] Rebooting in 86400 seconds..