[ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.18' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 34.119624] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program executing program [ 34.168018] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. [ 34.202577] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program [ 34.241775] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program [ 34.291695] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program [ 34.342736] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program executing program [ 34.392715] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. [ 34.432431] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program [ 34.472321] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program [ 34.521859] netlink: 4 bytes leftover after parsing attributes in process `syz-executor086'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.126087] ================================================================== [ 38.133812] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 [ 38.141144] Read of size 4 at addr ffff8880ab292b58 by task syz-executor086/8743 [ 38.148835] [ 38.150454] CPU: 1 PID: 8743 Comm: syz-executor086 Not tainted 4.19.190-syzkaller #0 [ 38.158516] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.167948] Call Trace: [ 38.171004] dump_stack+0x1fc/0x2ef [ 38.174729] print_address_description.cold+0x54/0x219 [ 38.180095] kasan_report_error.cold+0x8a/0x1b9 [ 38.184770] ? refcount_dec_not_one+0x71/0x1d0 [ 38.189358] kasan_report+0x8f/0xa0 [ 38.192992] ? refcount_dec_not_one+0x71/0x1d0 [ 38.197565] refcount_dec_not_one+0x71/0x1d0 [ 38.201961] ? refcount_dec_and_test_checked+0x20/0x20 [ 38.207229] ? nbd_config_put+0x5da/0x870 [ 38.211367] refcount_dec_and_mutex_lock+0x1c/0x80 [ 38.216291] nbd_genl_connect+0x11ee/0x1630 [ 38.220637] ? nbd_xmit_timeout+0x730/0x730 [ 38.224961] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 38.230746] ? validate_nla+0x270/0x820 [ 38.234707] ? nla_parse+0x1b2/0x290 [ 38.238494] genl_family_rcv_msg+0x642/0xc40 [ 38.242979] ? genl_rcv+0x40/0x40 [ 38.246417] ? genl_rcv_msg+0x12f/0x160 [ 38.250379] ? __mutex_add_waiter+0x160/0x160 [ 38.254979] ? __radix_tree_lookup+0x216/0x370 [ 38.259554] genl_rcv_msg+0xbf/0x160 [ 38.263258] netlink_rcv_skb+0x160/0x440 [ 38.267312] ? genl_family_rcv_msg+0xc40/0xc40 [ 38.271886] ? netlink_ack+0xae0/0xae0 [ 38.275759] ? genl_rcv+0x15/0x40 [ 38.279604] genl_rcv+0x24/0x40 [ 38.282874] netlink_unicast+0x4d5/0x690 [ 38.286924] ? netlink_sendskb+0x110/0x110 [ 38.291265] ? _copy_from_iter_full+0x229/0x7c0 [ 38.296166] ? __phys_addr_symbol+0x2c/0x70 [ 38.300582] ? __check_object_size+0x17b/0x3e0 [ 38.305157] netlink_sendmsg+0x6bb/0xc40 [ 38.309341] ? aa_af_perm+0x230/0x230 [ 38.313147] ? nlmsg_notify+0x1a0/0x1a0 [ 38.317117] ? kernel_recvmsg+0x220/0x220 [ 38.321441] ? nlmsg_notify+0x1a0/0x1a0 [ 38.325407] sock_sendmsg+0xc3/0x120 [ 38.329131] ___sys_sendmsg+0x7bb/0x8e0 [ 38.333096] ? copy_msghdr_from_user+0x440/0x440 [ 38.337911] ? netlink_dump+0xc10/0xc10 [ 38.341900] ? nlmsg_notify+0x1a0/0x1a0 [ 38.345966] ? security_socket_recvmsg+0x8f/0xc0 [ 38.350739] ? __sys_recvfrom+0x2cd/0x3a0 [ 38.354881] ? __ia32_sys_send+0x100/0x100 [ 38.359111] ? __fdget+0x1a0/0x230 [ 38.362649] __x64_sys_sendmsg+0x132/0x220 [ 38.367157] ? __sys_sendmsg+0x1b0/0x1b0 [ 38.371231] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 38.376596] ? trace_hardirqs_off_caller+0x6e/0x210 [ 38.381775] ? do_syscall_64+0x21/0x620 [ 38.385846] do_syscall_64+0xf9/0x620 [ 38.389653] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.394917] RIP: 0033:0x440ec9 [ 38.398098] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 [ 38.417199] RSP: 002b:00007ffc372e0238 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 38.425007] RAX: ffffffffffffffda RBX: 00000000000094b6 RCX: 0000000000440ec9 [ 38.432267] RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000003 [ 38.439535] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc372e0260 [ 38.447277] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc372e025c [ 38.454535] R13: 00007ffc372e0290 R14: 00007ffc372e0270 R15: 0000000000000060 [ 38.461924] [ 38.463542] Allocated by task 8738: [ 38.467177] kmem_cache_alloc_trace+0x12f/0x380 [ 38.471831] nbd_dev_add+0x44/0x890 [ 38.475440] nbd_genl_connect+0x4cc/0x1630 [ 38.479661] genl_family_rcv_msg+0x642/0xc40 [ 38.484054] genl_rcv_msg+0xbf/0x160 [ 38.487758] netlink_rcv_skb+0x160/0x440 [ 38.491809] genl_rcv+0x24/0x40 [ 38.495187] netlink_unicast+0x4d5/0x690 [ 38.499235] netlink_sendmsg+0x6bb/0xc40 [ 38.503464] sock_sendmsg+0xc3/0x120 [ 38.507187] ___sys_sendmsg+0x7bb/0x8e0 [ 38.511161] __x64_sys_sendmsg+0x132/0x220 [ 38.515386] do_syscall_64+0xf9/0x620 [ 38.519185] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.524409] [ 38.526022] Freed by task 8743: [ 38.529291] kfree+0xcc/0x210 [ 38.532384] nbd_put.part.0+0xfe/0x140 [ 38.536259] nbd_config_put+0x6a0/0x870 [ 38.540218] nbd_genl_connect+0x11bb/0x1630 [ 38.544573] genl_family_rcv_msg+0x642/0xc40 [ 38.548966] genl_rcv_msg+0xbf/0x160 [ 38.552663] netlink_rcv_skb+0x160/0x440 [ 38.556747] genl_rcv+0x24/0x40 [ 38.560038] netlink_unicast+0x4d5/0x690 [ 38.564115] netlink_sendmsg+0x6bb/0xc40 [ 38.568182] sock_sendmsg+0xc3/0x120 [ 38.571895] ___sys_sendmsg+0x7bb/0x8e0 [ 38.575853] __x64_sys_sendmsg+0x132/0x220 [ 38.580178] do_syscall_64+0xf9/0x620 [ 38.583980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.589267] [ 38.591234] The buggy address belongs to the object at ffff8880ab292a80 [ 38.591234] which belongs to the cache kmalloc-512 of size 512 [ 38.604340] The buggy address is located 216 bytes inside of [ 38.604340] 512-byte region [ffff8880ab292a80, ffff8880ab292c80) [ 38.616322] The buggy address belongs to the page: [ 38.621247] page:ffffea0002aca480 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 38.629479] flags: 0xfff00000000100(slab) [ 38.633618] raw: 00fff00000000100 ffffea0002a8f808 ffffea0002a8ff88 ffff88813bff0940 [ 38.641836] raw: 0000000000000000 ffff8880ab292080 0000000100000006 0000000000000000 [ 38.649786] page dumped because: kasan: bad access detected [ 38.655895] [ 38.657609] Memory state around the buggy address: [ 38.662953] ffff8880ab292a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.671374] ffff8880ab292a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.678934] >ffff8880ab292b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.686476] ^ [ 38.693111] ffff8880ab292b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.701143] ffff8880ab292c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.708750] ================================================================== [ 38.716211] Disabling lock debugging due to kernel taint [ 38.722376] Kernel panic - not syncing: panic_on_warn set ... [ 38.722376] [ 38.729755] CPU: 1 PID: 8743 Comm: syz-executor086 Tainted: G B 4.19.190-syzkaller #0 [ 38.739022] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.748380] Call Trace: [ 38.750981] dump_stack+0x1fc/0x2ef [ 38.755314] panic+0x26a/0x50e [ 38.758528] ? __warn_printk+0xf3/0xf3 [ 38.762631] ? preempt_schedule_common+0x45/0xc0 [ 38.767382] ? ___preempt_schedule+0x16/0x18 [ 38.771784] ? trace_hardirqs_on+0x55/0x210 [ 38.776190] kasan_end_report+0x43/0x49 [ 38.780652] kasan_report_error.cold+0xa7/0x1b9 [ 38.785560] ? refcount_dec_not_one+0x71/0x1d0 [ 38.790144] kasan_report+0x8f/0xa0 [ 38.793957] ? refcount_dec_not_one+0x71/0x1d0 [ 38.798577] refcount_dec_not_one+0x71/0x1d0 [ 38.802976] ? refcount_dec_and_test_checked+0x20/0x20 [ 38.808452] ? nbd_config_put+0x5da/0x870 [ 38.812689] refcount_dec_and_mutex_lock+0x1c/0x80 [ 38.817615] nbd_genl_connect+0x11ee/0x1630 [ 38.821932] ? nbd_xmit_timeout+0x730/0x730 [ 38.826382] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 38.831580] ? validate_nla+0x270/0x820 [ 38.835737] ? nla_parse+0x1b2/0x290 [ 38.839443] genl_family_rcv_msg+0x642/0xc40 [ 38.843960] ? genl_rcv+0x40/0x40 [ 38.847550] ? genl_rcv_msg+0x12f/0x160 [ 38.851688] ? __mutex_add_waiter+0x160/0x160 [ 38.856368] ? __radix_tree_lookup+0x216/0x370 [ 38.861063] genl_rcv_msg+0xbf/0x160 [ 38.865058] netlink_rcv_skb+0x160/0x440 [ 38.869148] ? genl_family_rcv_msg+0xc40/0xc40 [ 38.873722] ? netlink_ack+0xae0/0xae0 [ 38.877602] ? genl_rcv+0x15/0x40 [ 38.881206] genl_rcv+0x24/0x40 [ 38.884576] netlink_unicast+0x4d5/0x690 [ 38.888901] ? netlink_sendskb+0x110/0x110 [ 38.893134] ? _copy_from_iter_full+0x229/0x7c0 [ 38.897805] ? __phys_addr_symbol+0x2c/0x70 [ 38.902248] ? __check_object_size+0x17b/0x3e0 [ 38.907183] netlink_sendmsg+0x6bb/0xc40 [ 38.911483] ? aa_af_perm+0x230/0x230 [ 38.915370] ? nlmsg_notify+0x1a0/0x1a0 [ 38.919422] ? kernel_recvmsg+0x220/0x220 [ 38.923669] ? nlmsg_notify+0x1a0/0x1a0 [ 38.927649] sock_sendmsg+0xc3/0x120 [ 38.931441] ___sys_sendmsg+0x7bb/0x8e0 [ 38.935404] ? copy_msghdr_from_user+0x440/0x440 [ 38.940253] ? netlink_dump+0xc10/0xc10 [ 38.944215] ? nlmsg_notify+0x1a0/0x1a0 [ 38.948178] ? security_socket_recvmsg+0x8f/0xc0 [ 38.953178] ? __sys_recvfrom+0x2cd/0x3a0 [ 38.957939] ? __ia32_sys_send+0x100/0x100 [ 38.962377] ? __fdget+0x1a0/0x230 [ 38.965939] __x64_sys_sendmsg+0x132/0x220 [ 38.970372] ? __sys_sendmsg+0x1b0/0x1b0 [ 38.974428] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 38.979915] ? trace_hardirqs_off_caller+0x6e/0x210 [ 38.984921] ? do_syscall_64+0x21/0x620 [ 38.989090] do_syscall_64+0xf9/0x620 [ 38.993155] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.998538] RIP: 0033:0x440ec9 [ 39.001720] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 [ 39.020702] RSP: 002b:00007ffc372e0238 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 39.028415] RAX: ffffffffffffffda RBX: 00000000000094b6 RCX: 0000000000440ec9 [ 39.037581] RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000003 [ 39.044938] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc372e0260 [ 39.052489] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc372e025c [ 39.060070] R13: 00007ffc372e0290 R14: 00007ffc372e0270 R15: 0000000000000060 [ 39.068383] Kernel Offset: disabled [ 39.072004] Rebooting in 86400 seconds..