Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.30' (ECDSA) to the list of known hosts. 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 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 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 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 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 syzkaller login: [ 42.143941] ================================================================== [ 42.151665] BUG: KASAN: use-after-free in ex_handler_refcount+0x18f/0x1c0 [ 42.159064] Write of size 4 at addr ffff8880b4859898 by task systemd-udevd/9490 [ 42.166669] [ 42.168289] CPU: 0 PID: 9490 Comm: systemd-udevd Not tainted 4.19.190-syzkaller #0 [ 42.175979] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.185327] Call Trace: [ 42.187923] dump_stack+0x1fc/0x2ef [ 42.191540] print_address_description.cold+0x54/0x219 [ 42.196910] kasan_report_error.cold+0x8a/0x1b9 [ 42.201747] ? ex_handler_refcount+0x18f/0x1c0 [ 42.206313] __asan_report_store4_noabort+0x88/0x90 [ 42.211315] ? notify_die+0x71/0x170 [ 42.215011] ? ex_handler_refcount+0x18f/0x1c0 [ 42.219596] ex_handler_refcount+0x18f/0x1c0 [ 42.224006] ? ex_handler_clear_fs+0xb0/0xb0 [ 42.228398] fixup_exception+0x8a/0xd0 [ 42.232327] do_trap+0x61/0x250 [ 42.235678] ? do_error_trap+0x212/0x310 [ 42.239720] do_error_trap+0x15d/0x310 [ 42.243592] ? math_error+0x310/0x310 [ 42.247376] ? __noinstr_text_end+0x2446/0x77e7 [ 42.252029] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.256891] invalid_op+0x14/0x20 [ 42.260352] RIP: 0010:__noinstr_text_end+0x2446/0x77e7 [ 42.265612] 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 [ 42.284586] RSP: 0018:ffff8880a1047cd8 EFLAGS: 00010296 [ 42.289948] RAX: 0000000000000000 RBX: ffff8880b4859898 RCX: ffff8880b4859898 [ 42.297227] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 42.304592] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7829 [ 42.311942] R10: ffffffff8a5bc14b R11: 0000000000000000 R12: ffffffff8a5bc140 [ 42.319223] R13: 0000000000000000 R14: 1ffff110113f4b1d R15: dffffc0000000000 [ 42.326680] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 42.331789] nbd_release+0x108/0x170 [ 42.335489] ? nbd_queue_rq+0xe60/0xe60 [ 42.339446] __blkdev_put+0x636/0x870 [ 42.343249] ? fsync_bdev+0xc0/0xc0 [ 42.346886] ? locks_remove_file+0x2cd/0x450 [ 42.351310] ? blkdev_put+0x85/0x520 [ 42.355197] ? blkdev_put+0x520/0x520 [ 42.359080] blkdev_close+0x86/0xb0 [ 42.363082] __fput+0x2ce/0x890 [ 42.366462] task_work_run+0x148/0x1c0 [ 42.370441] exit_to_usermode_loop+0x251/0x2a0 [ 42.375011] do_syscall_64+0x538/0x620 [ 42.378906] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.384081] RIP: 0033:0x7f9dd32ca270 [ 42.387781] 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 [ 42.406697] RSP: 002b:00007ffc4d2cbb58 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 42.414397] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f9dd32ca270 [ 42.421660] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 42.429209] RBP: 00007f9dd4184710 R08: 0000555c4014f3a0 R09: 0000000000000018 [ 42.436478] R10: 0000555c4014f5d8 R11: 0000000000000246 R12: 0000000000000000 [ 42.443794] R13: 0000555c4015d6e0 R14: 0000000000000003 R15: 000000000000000e [ 42.451058] [ 42.452670] Allocated by task 9473: [ 42.456285] kmem_cache_alloc_trace+0x12f/0x380 [ 42.461171] nbd_dev_add+0x44/0x890 [ 42.464835] nbd_genl_connect+0x4cc/0x1630 [ 42.469064] genl_family_rcv_msg+0x642/0xc40 [ 42.473730] genl_rcv_msg+0xbf/0x160 [ 42.477444] netlink_rcv_skb+0x160/0x440 [ 42.481504] genl_rcv+0x24/0x40 [ 42.484768] netlink_unicast+0x4d5/0x690 [ 42.488827] netlink_sendmsg+0x6bb/0xc40 [ 42.493077] sock_sendmsg+0xc3/0x120 [ 42.496877] ___sys_sendmsg+0x7bb/0x8e0 [ 42.500947] __x64_sys_sendmsg+0x132/0x220 [ 42.505207] do_syscall_64+0xf9/0x620 [ 42.508995] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.514341] [ 42.515957] Freed by task 9496: [ 42.519231] kfree+0xcc/0x210 [ 42.522337] nbd_put.part.0+0xfe/0x140 [ 42.526295] nbd_genl_connect+0x120e/0x1630 [ 42.530701] genl_family_rcv_msg+0x642/0xc40 [ 42.535096] genl_rcv_msg+0xbf/0x160 [ 42.538819] netlink_rcv_skb+0x160/0x440 [ 42.542951] genl_rcv+0x24/0x40 [ 42.546214] netlink_unicast+0x4d5/0x690 [ 42.550271] netlink_sendmsg+0x6bb/0xc40 [ 42.554337] sock_sendmsg+0xc3/0x120 [ 42.558038] ___sys_sendmsg+0x7bb/0x8e0 [ 42.561993] __x64_sys_sendmsg+0x132/0x220 [ 42.566219] do_syscall_64+0xf9/0x620 [ 42.570014] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.575183] [ 42.576794] The buggy address belongs to the object at ffff8880b48597c0 [ 42.576794] which belongs to the cache kmalloc-512 of size 512 [ 42.589554] The buggy address is located 216 bytes inside of [ 42.589554] 512-byte region [ffff8880b48597c0, ffff8880b48599c0) [ 42.601427] The buggy address belongs to the page: [ 42.606357] page:ffffea0002d21640 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 42.614496] flags: 0xfff00000000100(slab) [ 42.618631] raw: 00fff00000000100 ffffea0002643c08 ffffea00025f6548 ffff88813bff0940 [ 42.626777] raw: 0000000000000000 ffff8880b4859040 0000000100000006 0000000000000000 [ 42.634638] page dumped because: kasan: bad access detected [ 42.640343] [ 42.641967] Memory state around the buggy address: [ 42.646981] ffff8880b4859780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 42.654332] ffff8880b4859800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.661697] >ffff8880b4859880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.669040] ^ [ 42.673188] ffff8880b4859900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.680707] ffff8880b4859980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 42.688043] ================================================================== [ 42.695386] Disabling lock debugging due to kernel taint [ 42.705483] Kernel panic - not syncing: panic_on_warn set ... [ 42.705483] [ 42.712877] CPU: 0 PID: 9490 Comm: systemd-udevd Tainted: G B 4.19.190-syzkaller #0 [ 42.721972] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.731334] Call Trace: [ 42.733921] dump_stack+0x1fc/0x2ef [ 42.737530] panic+0x26a/0x50e [ 42.740703] ? __warn_printk+0xf3/0xf3 [ 42.744586] ? preempt_schedule_common+0x45/0xc0 [ 42.749671] ? ___preempt_schedule+0x16/0x18 [ 42.754064] ? trace_hardirqs_on+0x55/0x210 [ 42.758384] kasan_end_report+0x43/0x49 [ 42.762341] kasan_report_error.cold+0xa7/0x1b9 [ 42.766993] ? ex_handler_refcount+0x18f/0x1c0 [ 42.771557] __asan_report_store4_noabort+0x88/0x90 [ 42.776644] ? notify_die+0x71/0x170 [ 42.780338] ? ex_handler_refcount+0x18f/0x1c0 [ 42.784988] ex_handler_refcount+0x18f/0x1c0 [ 42.789399] ? ex_handler_clear_fs+0xb0/0xb0 [ 42.793819] fixup_exception+0x8a/0xd0 [ 42.797801] do_trap+0x61/0x250 [ 42.801061] ? do_error_trap+0x212/0x310 [ 42.805134] do_error_trap+0x15d/0x310 [ 42.809094] ? math_error+0x310/0x310 [ 42.812979] ? __noinstr_text_end+0x2446/0x77e7 [ 42.817813] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.822643] invalid_op+0x14/0x20 [ 42.826078] RIP: 0010:__noinstr_text_end+0x2446/0x77e7 [ 42.831427] 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 [ 42.850597] RSP: 0018:ffff8880a1047cd8 EFLAGS: 00010296 [ 42.855953] RAX: 0000000000000000 RBX: ffff8880b4859898 RCX: ffff8880b4859898 [ 42.863466] RDX: 0000000000000004 RSI: 0000000000000004 RDI: 0000000000000001 [ 42.870724] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff14b7829 [ 42.877987] R10: ffffffff8a5bc14b R11: 0000000000000000 R12: ffffffff8a5bc140 [ 42.887243] R13: 0000000000000000 R14: 1ffff110113f4b1d R15: dffffc0000000000 [ 42.894518] ? refcount_dec_and_mutex_lock+0x4a/0x80 [ 42.899610] nbd_release+0x108/0x170 [ 42.903314] ? nbd_queue_rq+0xe60/0xe60 [ 42.907287] __blkdev_put+0x636/0x870 [ 42.911086] ? fsync_bdev+0xc0/0xc0 [ 42.914716] ? locks_remove_file+0x2cd/0x450 [ 42.919295] ? blkdev_put+0x85/0x520 [ 42.922990] ? blkdev_put+0x520/0x520 [ 42.926779] blkdev_close+0x86/0xb0 [ 42.930393] __fput+0x2ce/0x890 [ 42.933658] task_work_run+0x148/0x1c0 [ 42.937530] exit_to_usermode_loop+0x251/0x2a0 [ 42.942121] do_syscall_64+0x538/0x620 [ 42.946014] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.951187] RIP: 0033:0x7f9dd32ca270 [ 42.954984] 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 [ 42.973879] RSP: 002b:00007ffc4d2cbb58 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 42.981589] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f9dd32ca270 [ 42.988851] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 42.996116] RBP: 00007f9dd4184710 R08: 0000555c4014f3a0 R09: 0000000000000018 [ 43.003369] R10: 0000555c4014f5d8 R11: 0000000000000246 R12: 0000000000000000 [ 43.013117] R13: 0000555c4015d6e0 R14: 0000000000000003 R15: 000000000000000e [ 43.022083] Kernel Offset: disabled [ 43.026038] Rebooting in 86400 seconds..