Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.118' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 32.473832] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. [ 32.482711] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. executing program [ 32.547973] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. [ 32.556787] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. executing program executing program [ 32.616773] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. [ 32.625633] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. executing program [ 32.676062] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. [ 32.684740] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. executing program [ 32.737022] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. [ 32.745766] netlink: 4 bytes leftover after parsing attributes in process `syz-executor856'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 36.431006] ================================================================== [ 36.438749] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1d0 [ 36.445800] Read of size 4 at addr ffff8880a88c4398 by task syz-executor856/8743 [ 36.453352] [ 36.454972] CPU: 1 PID: 8743 Comm: syz-executor856 Not tainted 4.19.194-syzkaller #0 [ 36.462830] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.472168] Call Trace: [ 36.474744] dump_stack+0x1fc/0x2ef [ 36.478377] print_address_description.cold+0x54/0x219 [ 36.483645] kasan_report_error.cold+0x8a/0x1b9 [ 36.488298] ? refcount_dec_not_one+0x71/0x1d0 [ 36.492883] kasan_report+0x8f/0xa0 [ 36.496499] ? refcount_dec_not_one+0x71/0x1d0 [ 36.501091] refcount_dec_not_one+0x71/0x1d0 [ 36.505490] ? refcount_dec_and_test_checked+0x20/0x20 [ 36.510754] ? nbd_config_put+0x5da/0x870 [ 36.514888] refcount_dec_and_mutex_lock+0x1c/0x80 [ 36.519817] nbd_genl_connect+0x11ee/0x1630 [ 36.524127] ? nbd_xmit_timeout+0x730/0x730 [ 36.528439] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 36.533621] ? validate_nla+0x270/0x820 [ 36.537601] ? nla_parse+0x1b2/0x290 [ 36.541321] genl_family_rcv_msg+0x642/0xc40 [ 36.545730] ? genl_rcv+0x40/0x40 [ 36.549169] ? genl_rcv_msg+0x12f/0x160 [ 36.553140] ? mutex_trylock+0x1a0/0x1a0 [ 36.557189] ? __radix_tree_lookup+0x216/0x370 [ 36.561765] genl_rcv_msg+0xbf/0x160 [ 36.565477] netlink_rcv_skb+0x160/0x440 [ 36.569521] ? genl_family_rcv_msg+0xc40/0xc40 [ 36.574087] ? netlink_ack+0xae0/0xae0 [ 36.577958] ? genl_rcv+0x15/0x40 [ 36.581396] genl_rcv+0x24/0x40 [ 36.584663] netlink_unicast+0x4d5/0x690 [ 36.588720] ? netlink_sendskb+0x110/0x110 [ 36.592967] ? _copy_from_iter_full+0x229/0x7c0 [ 36.597617] ? __phys_addr_symbol+0x2c/0x70 [ 36.601935] ? __check_object_size+0x17b/0x3e0 [ 36.606512] netlink_sendmsg+0x6bb/0xc40 [ 36.610564] ? aa_af_perm+0x230/0x230 [ 36.614349] ? nlmsg_notify+0x1a0/0x1a0 [ 36.618403] ? kernel_recvmsg+0x220/0x220 [ 36.622557] ? nlmsg_notify+0x1a0/0x1a0 [ 36.626518] sock_sendmsg+0xc3/0x120 [ 36.630221] ___sys_sendmsg+0x7bb/0x8e0 [ 36.634182] ? copy_msghdr_from_user+0x440/0x440 [ 36.638924] ? netlink_dump+0xc10/0xc10 [ 36.642890] ? nlmsg_notify+0x1a0/0x1a0 [ 36.646861] ? security_socket_recvmsg+0x8f/0xc0 [ 36.651609] ? __sys_recvfrom+0x2cd/0x3a0 [ 36.655752] ? __ia32_sys_send+0x100/0x100 [ 36.659973] ? __fdget+0x1a0/0x230 [ 36.663510] __x64_sys_sendmsg+0x132/0x220 [ 36.667728] ? __sys_sendmsg+0x1b0/0x1b0 [ 36.671779] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 36.677136] ? trace_hardirqs_off_caller+0x6e/0x210 [ 36.682242] ? do_syscall_64+0x21/0x620 [ 36.686223] do_syscall_64+0xf9/0x620 [ 36.690012] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.695204] RIP: 0033:0x441409 [ 36.698377] 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 c4 ff ff ff f7 d8 64 89 01 48 [ 36.717258] RSP: 002b:00007fff83cf6e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 36.724949] RAX: ffffffffffffffda RBX: 0000000000008dec RCX: 0000000000441409 [ 36.732204] RDX: 0000000020000010 RSI: 0000000020000980 RDI: 0000000000000003 [ 36.739453] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 36.746703] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff83cf6ebc [ 36.753951] R13: 431bde82d7b634db R14: 00007fff83cf6ed0 R15: 00000000004004a0 [ 36.761219] [ 36.762844] Allocated by task 8739: [ 36.766468] kmem_cache_alloc_trace+0x12f/0x380 [ 36.771141] nbd_dev_add+0x44/0x890 [ 36.774751] nbd_genl_connect+0x4cc/0x1630 [ 36.778970] genl_family_rcv_msg+0x642/0xc40 [ 36.783361] genl_rcv_msg+0xbf/0x160 [ 36.787056] netlink_rcv_skb+0x160/0x440 [ 36.791099] genl_rcv+0x24/0x40 [ 36.794359] netlink_unicast+0x4d5/0x690 [ 36.798415] netlink_sendmsg+0x6bb/0xc40 [ 36.802548] sock_sendmsg+0xc3/0x120 [ 36.806259] ___sys_sendmsg+0x7bb/0x8e0 [ 36.810214] __x64_sys_sendmsg+0x132/0x220 [ 36.814433] do_syscall_64+0xf9/0x620 [ 36.818215] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.823382] [ 36.824990] Freed by task 8743: [ 36.828257] kfree+0xcc/0x210 [ 36.831347] nbd_put.part.0+0xfe/0x140 [ 36.835222] nbd_config_put+0x6a0/0x870 [ 36.839182] nbd_genl_connect+0x11bb/0x1630 [ 36.843494] genl_family_rcv_msg+0x642/0xc40 [ 36.847898] genl_rcv_msg+0xbf/0x160 [ 36.851592] netlink_rcv_skb+0x160/0x440 [ 36.855633] genl_rcv+0x24/0x40 [ 36.858917] netlink_unicast+0x4d5/0x690 [ 36.862972] netlink_sendmsg+0x6bb/0xc40 [ 36.867015] sock_sendmsg+0xc3/0x120 [ 36.870738] ___sys_sendmsg+0x7bb/0x8e0 [ 36.874797] __x64_sys_sendmsg+0x132/0x220 [ 36.879019] do_syscall_64+0xf9/0x620 [ 36.882809] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.887972] [ 36.889599] The buggy address belongs to the object at ffff8880a88c42c0 [ 36.889599] which belongs to the cache kmalloc-512 of size 512 [ 36.902237] The buggy address is located 216 bytes inside of [ 36.902237] 512-byte region [ffff8880a88c42c0, ffff8880a88c44c0) [ 36.914094] The buggy address belongs to the page: [ 36.919009] page:ffffea0002a23100 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0 [ 36.927130] flags: 0xfff00000000100(slab) [ 36.931264] raw: 00fff00000000100 ffffea0002a3b808 ffffea0002ad7f08 ffff88813bff0940 [ 36.939130] raw: 0000000000000000 ffff8880a88c4040 0000000100000006 0000000000000000 [ 36.946991] page dumped because: kasan: bad access detected [ 36.952724] [ 36.954343] Memory state around the buggy address: [ 36.959254] ffff8880a88c4280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 36.966598] ffff8880a88c4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.973943] >ffff8880a88c4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.981282] ^ [ 36.985416] ffff8880a88c4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.992759] ffff8880a88c4480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 37.000099] ================================================================== [ 37.007439] Disabling lock debugging due to kernel taint [ 37.013781] Kernel panic - not syncing: panic_on_warn set ... [ 37.013781] [ 37.021177] CPU: 1 PID: 8743 Comm: syz-executor856 Tainted: G B 4.19.194-syzkaller #0 [ 37.030478] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.039852] Call Trace: [ 37.042456] dump_stack+0x1fc/0x2ef [ 37.046097] panic+0x26a/0x50e [ 37.049298] ? __warn_printk+0xf3/0xf3 [ 37.053202] ? preempt_schedule_common+0x45/0xc0 [ 37.057960] ? ___preempt_schedule+0x16/0x18 [ 37.062355] ? trace_hardirqs_on+0x55/0x210 [ 37.066661] kasan_end_report+0x43/0x49 [ 37.070619] kasan_report_error.cold+0xa7/0x1b9 [ 37.075284] ? refcount_dec_not_one+0x71/0x1d0 [ 37.079845] kasan_report+0x8f/0xa0 [ 37.083468] ? refcount_dec_not_one+0x71/0x1d0 [ 37.088036] refcount_dec_not_one+0x71/0x1d0 [ 37.092540] ? refcount_dec_and_test_checked+0x20/0x20 [ 37.097800] ? nbd_config_put+0x5da/0x870 [ 37.101945] refcount_dec_and_mutex_lock+0x1c/0x80 [ 37.106871] nbd_genl_connect+0x11ee/0x1630 [ 37.111199] ? nbd_xmit_timeout+0x730/0x730 [ 37.115509] ? __sanitizer_cov_trace_switch+0x4b/0x80 [ 37.120684] ? validate_nla+0x270/0x820 [ 37.124658] ? nla_parse+0x1b2/0x290 [ 37.128356] genl_family_rcv_msg+0x642/0xc40 [ 37.132748] ? genl_rcv+0x40/0x40 [ 37.136181] ? genl_rcv_msg+0x12f/0x160 [ 37.140138] ? mutex_trylock+0x1a0/0x1a0 [ 37.144207] ? __radix_tree_lookup+0x216/0x370 [ 37.148774] genl_rcv_msg+0xbf/0x160 [ 37.152481] netlink_rcv_skb+0x160/0x440 [ 37.156525] ? genl_family_rcv_msg+0xc40/0xc40 [ 37.161088] ? netlink_ack+0xae0/0xae0 [ 37.164964] ? genl_rcv+0x15/0x40 [ 37.168400] genl_rcv+0x24/0x40 [ 37.171668] netlink_unicast+0x4d5/0x690 [ 37.175711] ? netlink_sendskb+0x110/0x110 [ 37.179936] ? _copy_from_iter_full+0x229/0x7c0 [ 37.184586] ? __phys_addr_symbol+0x2c/0x70 [ 37.188891] ? __check_object_size+0x17b/0x3e0 [ 37.193476] netlink_sendmsg+0x6bb/0xc40 [ 37.197520] ? aa_af_perm+0x230/0x230 [ 37.201306] ? nlmsg_notify+0x1a0/0x1a0 [ 37.205265] ? kernel_recvmsg+0x220/0x220 [ 37.209396] ? nlmsg_notify+0x1a0/0x1a0 [ 37.213411] sock_sendmsg+0xc3/0x120 [ 37.217124] ___sys_sendmsg+0x7bb/0x8e0 [ 37.221154] ? copy_msghdr_from_user+0x440/0x440 [ 37.225902] ? netlink_dump+0xc10/0xc10 [ 37.229860] ? nlmsg_notify+0x1a0/0x1a0 [ 37.233822] ? security_socket_recvmsg+0x8f/0xc0 [ 37.238671] ? __sys_recvfrom+0x2cd/0x3a0 [ 37.242803] ? __ia32_sys_send+0x100/0x100 [ 37.247026] ? __fdget+0x1a0/0x230 [ 37.250555] __x64_sys_sendmsg+0x132/0x220 [ 37.254773] ? __sys_sendmsg+0x1b0/0x1b0 [ 37.258827] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 37.264256] ? trace_hardirqs_off_caller+0x6e/0x210 [ 37.269290] ? do_syscall_64+0x21/0x620 [ 37.273341] do_syscall_64+0xf9/0x620 [ 37.277263] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.282454] RIP: 0033:0x441409 [ 37.285633] 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 c4 ff ff ff f7 d8 64 89 01 48 [ 37.304534] RSP: 002b:00007fff83cf6e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 37.312239] RAX: ffffffffffffffda RBX: 0000000000008dec RCX: 0000000000441409 [ 37.319501] RDX: 0000000020000010 RSI: 0000000020000980 RDI: 0000000000000003 [ 37.326749] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 37.334003] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff83cf6ebc [ 37.341255] R13: 431bde82d7b634db R14: 00007fff83cf6ed0 R15: 00000000004004a0 [ 37.349367] Kernel Offset: disabled [ 37.352981] Rebooting in 86400 seconds..