[ 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 '10.128.0.42' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 42.830587] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.839813] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.849719] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.858959] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. executing program executing program [ 42.924024] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.933064] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.943329] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 42.952546] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. executing program [ 43.001992] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. [ 43.010809] netlink: 4 bytes leftover after parsing attributes in process `syz-executor766'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 44.938883] ================================================================== [ 44.946436] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 [ 44.953415] Read of size 4 at addr ffff8880a9acd918 by task syz-executor766/8504 [ 44.960922] [ 44.962537] CPU: 1 PID: 8504 Comm: syz-executor766 Not tainted 4.19.189-syzkaller #0 [ 44.970391] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.979721] Call Trace: [ 44.982324] dump_stack+0x1fc/0x2ef [ 44.986042] print_address_description.cold+0x54/0x219 [ 44.991299] kasan_report_error.cold+0x8a/0x1b9 [ 44.995954] ? refcount_dec_not_one+0x71/0x1d0 [ 45.000644] kasan_report+0x8f/0xa0 [ 45.004250] ? refcount_dec_not_one+0x71/0x1d0 [ 45.008920] refcount_dec_not_one+0x71/0x1d0 [ 45.013309] ? refcount_dec_and_test_checked+0x20/0x20 [ 45.018698] ? nbd_config_put+0x5da/0x870 [ 45.022824] refcount_dec_and_mutex_lock+0x1c/0x80 [ 45.027733] nbd_genl_connect+0x11ee/0x1630 [ 45.032035] ? nbd_xmit_timeout+0x730/0x730 [ 45.036349] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 45.041518] ? validate_nla+0x270/0x820 [ 45.045476] ? nla_parse+0x1b2/0x290 [ 45.049176] genl_family_rcv_msg+0x642/0xc40 [ 45.053567] ? genl_rcv+0x40/0x40 [ 45.057000] ? genl_rcv_msg+0x12f/0x160 [ 45.060971] ? __mutex_add_waiter+0x160/0x160 [ 45.065455] ? __radix_tree_lookup+0x216/0x370 [ 45.070040] genl_rcv_msg+0xbf/0x160 [ 45.073738] netlink_rcv_skb+0x160/0x440 [ 45.077781] ? genl_family_rcv_msg+0xc40/0xc40 [ 45.082457] ? netlink_ack+0xae0/0xae0 [ 45.086331] ? genl_rcv+0x15/0x40 [ 45.089768] genl_rcv+0x24/0x40 [ 45.093028] netlink_unicast+0x4d5/0x690 [ 45.097078] ? netlink_sendskb+0x110/0x110 [ 45.101294] ? _copy_from_iter_full+0x229/0x7c0 [ 45.105944] ? __phys_addr_symbol+0x2c/0x70 [ 45.110246] ? __check_object_size+0x17b/0x3e0 [ 45.114807] netlink_sendmsg+0x6bb/0xc40 [ 45.118847] ? aa_af_perm+0x230/0x230 [ 45.122626] ? nlmsg_notify+0x1a0/0x1a0 [ 45.126595] ? kernel_recvmsg+0x220/0x220 [ 45.130724] ? nlmsg_notify+0x1a0/0x1a0 [ 45.134685] sock_sendmsg+0xc3/0x120 [ 45.138381] ___sys_sendmsg+0x7bb/0x8e0 [ 45.142335] ? copy_msghdr_from_user+0x440/0x440 [ 45.147256] ? netlink_dump+0xc10/0xc10 [ 45.151220] ? nlmsg_notify+0x1a0/0x1a0 [ 45.155218] ? security_socket_recvmsg+0x8f/0xc0 [ 45.159978] ? __sys_recvfrom+0x2cd/0x3a0 [ 45.164107] ? __ia32_sys_send+0x100/0x100 [ 45.168340] ? __fdget+0x1a0/0x230 [ 45.172141] __x64_sys_sendmsg+0x132/0x220 [ 45.176377] ? __sys_sendmsg+0x1b0/0x1b0 [ 45.180474] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 45.185820] ? trace_hardirqs_off_caller+0x6e/0x210 [ 45.190818] ? do_syscall_64+0x21/0x620 [ 45.194792] do_syscall_64+0xf9/0x620 [ 45.198581] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.203750] RIP: 0033:0x440799 [ 45.206922] 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 [ 45.225801] RSP: 002b:00007ffdff24b798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 45.233603] RAX: ffffffffffffffda RBX: 000000000000af29 RCX: 0000000000440799 [ 45.240850] RDX: 0000000000040800 RSI: 0000000020000380 RDI: 0000000000000003 [ 45.248116] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffdff24b938 [ 45.255363] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdff24b7ac [ 45.262613] R13: 431bde82d7b634db R14: 00000000004ae018 R15: 00000000004004a0 [ 45.269876] [ 45.271626] Allocated by task 8497: [ 45.275253] kmem_cache_alloc_trace+0x12f/0x380 [ 45.279901] nbd_dev_add+0x44/0x890 [ 45.283519] nbd_genl_connect+0x4cc/0x1630 [ 45.287758] genl_family_rcv_msg+0x642/0xc40 [ 45.292145] genl_rcv_msg+0xbf/0x160 [ 45.295839] netlink_rcv_skb+0x160/0x440 [ 45.299921] genl_rcv+0x24/0x40 [ 45.303200] netlink_unicast+0x4d5/0x690 [ 45.307255] netlink_sendmsg+0x6bb/0xc40 [ 45.311300] sock_sendmsg+0xc3/0x120 [ 45.315010] ___sys_sendmsg+0x7bb/0x8e0 [ 45.318964] __x64_sys_sendmsg+0x132/0x220 [ 45.323279] do_syscall_64+0xf9/0x620 [ 45.327097] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.332267] [ 45.333917] Freed by task 8504: [ 45.337189] kfree+0xcc/0x210 [ 45.340282] nbd_put.part.0+0xfe/0x140 [ 45.344151] nbd_config_put+0x6a0/0x870 [ 45.348106] nbd_genl_connect+0x11bb/0x1630 [ 45.352423] genl_family_rcv_msg+0x642/0xc40 [ 45.356914] genl_rcv_msg+0xbf/0x160 [ 45.360623] netlink_rcv_skb+0x160/0x440 [ 45.364747] genl_rcv+0x24/0x40 [ 45.368017] netlink_unicast+0x4d5/0x690 [ 45.372084] netlink_sendmsg+0x6bb/0xc40 [ 45.376124] sock_sendmsg+0xc3/0x120 [ 45.379818] ___sys_sendmsg+0x7bb/0x8e0 [ 45.383770] __x64_sys_sendmsg+0x132/0x220 [ 45.388013] do_syscall_64+0xf9/0x620 [ 45.391882] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.397060] [ 45.398669] The buggy address belongs to the object at ffff8880a9acd840 [ 45.398669] which belongs to the cache kmalloc-512 of size 512 [ 45.411316] The buggy address is located 216 bytes inside of [ 45.411316] 512-byte region [ffff8880a9acd840, ffff8880a9acda40) [ 45.423184] The buggy address belongs to the page: [ 45.428090] page:ffffea0002a6b340 count:1 mapcount:0 mapping:ffff88813bff0940 index:0xffff8880a9acd0c0 [ 45.437519] flags: 0xfff00000000100(slab) [ 45.441659] raw: 00fff00000000100 ffffea0002caf248 ffffea0002c49148 ffff88813bff0940 [ 45.449526] raw: ffff8880a9acd0c0 ffff8880a9acd0c0 0000000100000005 0000000000000000 [ 45.457393] page dumped because: kasan: bad access detected [ 45.463087] [ 45.464694] Memory state around the buggy address: [ 45.469602] ffff8880a9acd800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 45.476957] ffff8880a9acd880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.484293] >ffff8880a9acd900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.491624] ^ [ 45.495749] ffff8880a9acd980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.503088] ffff8880a9acda00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 45.510422] ================================================================== [ 45.517757] Disabling lock debugging due to kernel taint [ 45.527048] Kernel panic - not syncing: panic_on_warn set ... [ 45.527048] [ 45.534430] CPU: 0 PID: 8504 Comm: syz-executor766 Tainted: G B 4.19.189-syzkaller #0 [ 45.543700] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.553059] Call Trace: [ 45.555652] dump_stack+0x1fc/0x2ef [ 45.559277] panic+0x26a/0x50e [ 45.562468] ? __warn_printk+0xf3/0xf3 [ 45.566335] ? preempt_schedule_common+0x45/0xc0 [ 45.571069] ? ___preempt_schedule+0x16/0x18 [ 45.575467] ? trace_hardirqs_on+0x55/0x210 [ 45.579823] kasan_end_report+0x43/0x49 [ 45.583777] kasan_report_error.cold+0xa7/0x1b9 [ 45.588424] ? refcount_dec_not_one+0x71/0x1d0 [ 45.593167] kasan_report+0x8f/0xa0 [ 45.596769] ? refcount_dec_not_one+0x71/0x1d0 [ 45.601329] refcount_dec_not_one+0x71/0x1d0 [ 45.605727] ? refcount_dec_and_test_checked+0x20/0x20 [ 45.610991] ? nbd_config_put+0x5da/0x870 [ 45.615122] refcount_dec_and_mutex_lock+0x1c/0x80 [ 45.620059] nbd_genl_connect+0x11ee/0x1630 [ 45.624416] ? nbd_xmit_timeout+0x730/0x730 [ 45.628718] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 45.633903] ? validate_nla+0x270/0x820 [ 45.637861] ? nla_parse+0x1b2/0x290 [ 45.641556] genl_family_rcv_msg+0x642/0xc40 [ 45.645944] ? genl_rcv+0x40/0x40 [ 45.649394] ? genl_rcv_msg+0x12f/0x160 [ 45.653344] ? __mutex_add_waiter+0x160/0x160 [ 45.657830] ? __radix_tree_lookup+0x216/0x370 [ 45.662426] genl_rcv_msg+0xbf/0x160 [ 45.666122] netlink_rcv_skb+0x160/0x440 [ 45.670164] ? genl_family_rcv_msg+0xc40/0xc40 [ 45.674722] ? netlink_ack+0xae0/0xae0 [ 45.678623] ? genl_rcv+0x15/0x40 [ 45.682055] genl_rcv+0x24/0x40 [ 45.685313] netlink_unicast+0x4d5/0x690 [ 45.689364] ? netlink_sendskb+0x110/0x110 [ 45.693663] ? _copy_from_iter_full+0x229/0x7c0 [ 45.698308] ? __phys_addr_symbol+0x2c/0x70 [ 45.702609] ? __check_object_size+0x17b/0x3e0 [ 45.707168] netlink_sendmsg+0x6bb/0xc40 [ 45.711218] ? aa_af_perm+0x230/0x230 [ 45.714995] ? nlmsg_notify+0x1a0/0x1a0 [ 45.718946] ? kernel_recvmsg+0x220/0x220 [ 45.723157] ? nlmsg_notify+0x1a0/0x1a0 [ 45.727126] sock_sendmsg+0xc3/0x120 [ 45.730819] ___sys_sendmsg+0x7bb/0x8e0 [ 45.734773] ? copy_msghdr_from_user+0x440/0x440 [ 45.739508] ? netlink_dump+0xc10/0xc10 [ 45.743461] ? nlmsg_notify+0x1a0/0x1a0 [ 45.747425] ? security_socket_recvmsg+0x8f/0xc0 [ 45.752209] ? __sys_recvfrom+0x2cd/0x3a0 [ 45.756347] ? __ia32_sys_send+0x100/0x100 [ 45.760568] ? __fdget+0x1a0/0x230 [ 45.764101] __x64_sys_sendmsg+0x132/0x220 [ 45.768320] ? __sys_sendmsg+0x1b0/0x1b0 [ 45.772381] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 45.777732] ? trace_hardirqs_off_caller+0x6e/0x210 [ 45.782745] ? do_syscall_64+0x21/0x620 [ 45.786701] do_syscall_64+0xf9/0x620 [ 45.790485] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.795651] RIP: 0033:0x440799 [ 45.798825] 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 [ 45.817706] RSP: 002b:00007ffdff24b798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 45.825392] RAX: ffffffffffffffda RBX: 000000000000af29 RCX: 0000000000440799 [ 45.832660] RDX: 0000000000040800 RSI: 0000000020000380 RDI: 0000000000000003 [ 45.839907] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffdff24b938 [ 45.847155] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdff24b7ac [ 45.854402] R13: 431bde82d7b634db R14: 00000000004ae018 R15: 00000000004004a0 [ 45.862361] Kernel Offset: disabled [ 45.865990] Rebooting in 86400 seconds..