[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.98' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 32.739729] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 32.803349] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 32.852008] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 32.892339] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program executing program [ 32.942428] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. [ 32.982241] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 33.022173] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 33.072283] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program [ 33.123319] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program executing program [ 33.171868] netlink: 4 bytes leftover after parsing attributes in process `syz-executor414'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 36.361463] ================================================================== [ 36.368917] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 [ 36.375827] Read of size 4 at addr ffff8880a9b743d8 by task syz-executor414/8670 [ 36.383337] [ 36.384950] CPU: 1 PID: 8670 Comm: syz-executor414 Not tainted 4.19.211-syzkaller #0 [ 36.392806] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.402139] Call Trace: [ 36.404712] dump_stack+0x1fc/0x2ef [ 36.408339] print_address_description.cold+0x54/0x219 [ 36.413606] kasan_report_error.cold+0x8a/0x1b9 [ 36.418278] ? refcount_dec_not_one+0x71/0x1d0 [ 36.422855] kasan_report+0x8f/0xa0 [ 36.426478] ? refcount_dec_not_one+0x71/0x1d0 [ 36.431045] refcount_dec_not_one+0x71/0x1d0 [ 36.435436] ? refcount_dec_and_test_checked+0x20/0x20 [ 36.440703] ? nbd_config_put+0x5da/0x870 [ 36.444836] refcount_dec_and_mutex_lock+0x1c/0x80 [ 36.449755] nbd_genl_connect+0x11ee/0x1630 [ 36.454065] ? nbd_xmit_timeout+0x730/0x730 [ 36.458370] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 36.463542] ? validate_nla+0x270/0x820 [ 36.467509] ? nla_parse+0x1b2/0x290 [ 36.471215] genl_family_rcv_msg+0x642/0xc40 [ 36.475609] ? genl_rcv+0x40/0x40 [ 36.479038] ? genl_rcv_msg+0x12f/0x160 [ 36.482998] ? mutex_trylock+0x1a0/0x1a0 [ 36.487044] ? __radix_tree_lookup+0x216/0x370 [ 36.491617] genl_rcv_msg+0xbf/0x160 [ 36.495320] netlink_rcv_skb+0x160/0x440 [ 36.499373] ? genl_family_rcv_msg+0xc40/0xc40 [ 36.503937] ? netlink_ack+0xae0/0xae0 [ 36.507805] ? genl_rcv+0x15/0x40 [ 36.511241] genl_rcv+0x24/0x40 [ 36.514503] netlink_unicast+0x4d5/0x690 [ 36.518549] ? netlink_sendskb+0x110/0x110 [ 36.522777] ? _copy_from_iter_full+0x229/0x7c0 [ 36.527612] ? __phys_addr_symbol+0x2c/0x70 [ 36.532524] ? __check_object_size+0x17b/0x3e0 [ 36.537099] netlink_sendmsg+0x6c3/0xc50 [ 36.541153] ? aa_af_perm+0x230/0x230 [ 36.544961] ? nlmsg_notify+0x1f0/0x1f0 [ 36.548934] ? kernel_recvmsg+0x220/0x220 [ 36.553076] ? nlmsg_notify+0x1f0/0x1f0 [ 36.557038] sock_sendmsg+0xc3/0x120 [ 36.560744] ___sys_sendmsg+0x7bb/0x8e0 [ 36.564704] ? copy_msghdr_from_user+0x440/0x440 [ 36.569444] ? netlink_dump+0xc10/0xc10 [ 36.573421] ? nlmsg_notify+0x1f0/0x1f0 [ 36.577428] ? security_socket_recvmsg+0x8f/0xc0 [ 36.582167] ? __sys_recvfrom+0x2cd/0x3a0 [ 36.586306] ? __ia32_sys_send+0x100/0x100 [ 36.590527] ? __fdget+0x1a0/0x230 [ 36.594051] __x64_sys_sendmsg+0x132/0x220 [ 36.598266] ? __sys_sendmsg+0x1b0/0x1b0 [ 36.602316] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 36.607663] ? trace_hardirqs_off_caller+0x6e/0x210 [ 36.612658] ? do_syscall_64+0x21/0x620 [ 36.616614] do_syscall_64+0xf9/0x620 [ 36.620425] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.625595] RIP: 0033:0x7fd71b079999 [ 36.629297] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 [ 36.648375] RSP: 002b:00007fffb70c2928 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 36.656075] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fd71b079999 [ 36.663335] RDX: 0000000010040cd0 RSI: 0000000020000480 RDI: 0000000000000003 [ 36.670590] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 36.677845] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000008c6c [ 36.685097] R13: 00007fffb70c293c R14: 00007fffb70c2950 R15: 00007fffb70c2940 [ 36.692355] [ 36.693964] Allocated by task 8660: [ 36.697586] kmem_cache_alloc_trace+0x12f/0x380 [ 36.702256] nbd_dev_add+0x44/0x890 [ 36.705863] nbd_genl_connect+0x4cc/0x1630 [ 36.710078] genl_family_rcv_msg+0x642/0xc40 [ 36.714475] genl_rcv_msg+0xbf/0x160 [ 36.718168] netlink_rcv_skb+0x160/0x440 [ 36.722215] genl_rcv+0x24/0x40 [ 36.725485] netlink_unicast+0x4d5/0x690 [ 36.729539] netlink_sendmsg+0x6c3/0xc50 [ 36.733581] sock_sendmsg+0xc3/0x120 [ 36.737271] ___sys_sendmsg+0x7bb/0x8e0 [ 36.741237] __x64_sys_sendmsg+0x132/0x220 [ 36.745471] do_syscall_64+0xf9/0x620 [ 36.749259] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.754430] [ 36.756039] Freed by task 8670: [ 36.759299] kfree+0xcc/0x210 [ 36.762385] nbd_put.part.0+0xfe/0x140 [ 36.766256] nbd_config_put+0x6a0/0x870 [ 36.770207] nbd_genl_connect+0x11bb/0x1630 [ 36.774516] genl_family_rcv_msg+0x642/0xc40 [ 36.778918] genl_rcv_msg+0xbf/0x160 [ 36.782621] netlink_rcv_skb+0x160/0x440 [ 36.786664] genl_rcv+0x24/0x40 [ 36.789932] netlink_unicast+0x4d5/0x690 [ 36.793981] netlink_sendmsg+0x6c3/0xc50 [ 36.798030] sock_sendmsg+0xc3/0x120 [ 36.801730] ___sys_sendmsg+0x7bb/0x8e0 [ 36.805694] __x64_sys_sendmsg+0x132/0x220 [ 36.809920] do_syscall_64+0xf9/0x620 [ 36.813701] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.818869] [ 36.820480] The buggy address belongs to the object at ffff8880a9b74300 [ 36.820480] which belongs to the cache kmalloc-512 of size 512 [ 36.833124] The buggy address is located 216 bytes inside of [ 36.833124] 512-byte region [ffff8880a9b74300, ffff8880a9b74500) [ 36.845438] The buggy address belongs to the page: [ 36.850356] page:ffffea0002a6dd00 count:1 mapcount:0 mapping:ffff88813bff0940 index:0xffff8880a9b74d00 [ 36.859796] flags: 0xfff00000000100(slab) [ 36.863931] raw: 00fff00000000100 ffffea0002a67288 ffffea0002ab23c8 ffff88813bff0940 [ 36.871796] raw: ffff8880a9b74d00 ffff8880a9b74080 0000000100000004 0000000000000000 [ 36.879653] page dumped because: kasan: bad access detected [ 36.885338] [ 36.886943] Memory state around the buggy address: [ 36.891856] ffff8880a9b74280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 36.899542] ffff8880a9b74300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.906891] >ffff8880a9b74380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.914225] ^ [ 36.920438] ffff8880a9b74400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.927866] ffff8880a9b74480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.935228] ================================================================== [ 36.942573] Disabling lock debugging due to kernel taint [ 36.952594] Kernel panic - not syncing: panic_on_warn set ... [ 36.952594] [ 36.959975] CPU: 0 PID: 8670 Comm: syz-executor414 Tainted: G B 4.19.211-syzkaller #0 [ 36.969237] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.978581] Call Trace: [ 36.981168] dump_stack+0x1fc/0x2ef [ 36.984789] panic+0x26a/0x50e [ 36.987963] ? __warn_printk+0xf3/0xf3 [ 36.991846] ? preempt_schedule_common+0x45/0xc0 [ 36.996609] ? ___preempt_schedule+0x16/0x18 [ 37.001011] ? trace_hardirqs_on+0x55/0x210 [ 37.005319] kasan_end_report+0x43/0x49 [ 37.009274] kasan_report_error.cold+0xa7/0x1b9 [ 37.013924] ? refcount_dec_not_one+0x71/0x1d0 [ 37.018484] kasan_report+0x8f/0xa0 [ 37.022093] ? refcount_dec_not_one+0x71/0x1d0 [ 37.026654] refcount_dec_not_one+0x71/0x1d0 [ 37.031043] ? refcount_dec_and_test_checked+0x20/0x20 [ 37.036302] ? nbd_config_put+0x5da/0x870 [ 37.040430] refcount_dec_and_mutex_lock+0x1c/0x80 [ 37.045343] nbd_genl_connect+0x11ee/0x1630 [ 37.049647] ? nbd_xmit_timeout+0x730/0x730 [ 37.053948] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 37.059122] ? validate_nla+0x270/0x820 [ 37.063084] ? nla_parse+0x1b2/0x290 [ 37.066781] genl_family_rcv_msg+0x642/0xc40 [ 37.071170] ? genl_rcv+0x40/0x40 [ 37.074604] ? genl_rcv_msg+0x12f/0x160 [ 37.078559] ? mutex_trylock+0x1a0/0x1a0 [ 37.082602] ? __radix_tree_lookup+0x216/0x370 [ 37.087165] genl_rcv_msg+0xbf/0x160 [ 37.090856] netlink_rcv_skb+0x160/0x440 [ 37.094899] ? genl_family_rcv_msg+0xc40/0xc40 [ 37.099462] ? netlink_ack+0xae0/0xae0 [ 37.103332] ? genl_rcv+0x15/0x40 [ 37.106768] genl_rcv+0x24/0x40 [ 37.110026] netlink_unicast+0x4d5/0x690 [ 37.114067] ? netlink_sendskb+0x110/0x110 [ 37.118283] ? _copy_from_iter_full+0x229/0x7c0 [ 37.122933] ? __phys_addr_symbol+0x2c/0x70 [ 37.127238] ? __check_object_size+0x17b/0x3e0 [ 37.131800] netlink_sendmsg+0x6c3/0xc50 [ 37.135843] ? aa_af_perm+0x230/0x230 [ 37.139621] ? nlmsg_notify+0x1f0/0x1f0 [ 37.143572] ? kernel_recvmsg+0x220/0x220 [ 37.147696] ? nlmsg_notify+0x1f0/0x1f0 [ 37.151654] sock_sendmsg+0xc3/0x120 [ 37.155347] ___sys_sendmsg+0x7bb/0x8e0 [ 37.159306] ? copy_msghdr_from_user+0x440/0x440 [ 37.164037] ? netlink_dump+0xc10/0xc10 [ 37.167997] ? nlmsg_notify+0x1f0/0x1f0 [ 37.171953] ? security_socket_recvmsg+0x8f/0xc0 [ 37.176688] ? __sys_recvfrom+0x2cd/0x3a0 [ 37.180813] ? __ia32_sys_send+0x100/0x100 [ 37.185027] ? __fdget+0x1a0/0x230 [ 37.188544] __x64_sys_sendmsg+0x132/0x220 [ 37.192756] ? __sys_sendmsg+0x1b0/0x1b0 [ 37.197232] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 37.202577] ? trace_hardirqs_off_caller+0x6e/0x210 [ 37.207569] ? do_syscall_64+0x21/0x620 [ 37.211523] do_syscall_64+0xf9/0x620 [ 37.215306] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.220472] RIP: 0033:0x7fd71b079999 [ 37.224252] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 [ 37.243133] RSP: 002b:00007fffb70c2928 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 37.250817] RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fd71b079999 [ 37.258063] RDX: 0000000010040cd0 RSI: 0000000020000480 RDI: 0000000000000003 [ 37.265308] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 37.272579] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000008c6c [ 37.279829] R13: 00007fffb70c293c R14: 00007fffb70c2950 R15: 00007fffb70c2940 [ 37.287156] Kernel Offset: disabled [ 37.290779] Rebooting in 86400 seconds..