[ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ 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... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.158' (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 syzkaller login: [ 71.252746][ T8534] debugfs: Directory 'nbd0' with parent 'block' already present! executing program executing program executing program executing program executing program executing program executing program executing program [ 71.947785][ T8593] ================================================================== [ 71.956020][ T8593] BUG: KASAN: use-after-free in refcount_dec_not_one+0x71/0x1e0 [ 71.963666][ T8593] Read of size 4 at addr ffff888029fbe1a0 by task syz-executor700/8593 [ 71.971913][ T8593] [ 71.974229][ T8593] CPU: 1 PID: 8593 Comm: syz-executor700 Not tainted 5.11.0-rc7-syzkaller #0 [ 71.982980][ T8593] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.993077][ T8593] Call Trace: [ 71.996348][ T8593] dump_stack+0x107/0x163 [ 72.000686][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.005987][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.011277][ T8593] print_address_description.constprop.0.cold+0x5b/0x2f8 [ 72.018319][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.023639][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.029058][ T8593] kasan_report.cold+0x79/0xd5 [ 72.033831][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.039324][ T8593] check_memory_region+0x13d/0x180 [ 72.044440][ T8593] refcount_dec_not_one+0x71/0x1e0 [ 72.049554][ T8593] ? refcount_warn_saturate+0x1e0/0x1e0 [ 72.055107][ T8593] ? nbd_config_put+0x5d0/0x8c0 [ 72.060003][ T8593] refcount_dec_and_mutex_lock+0x19/0x140 [ 72.065720][ T8593] nbd_genl_connect+0xee7/0x1560 [ 72.070659][ T8593] ? nbd_start_device+0xd40/0xd40 [ 72.075714][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.081960][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x1b7/0x290 [ 72.089344][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0xaf/0x290 [ 72.096630][ T8593] genl_family_rcv_msg_doit+0x228/0x320 [ 72.102189][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x290/0x290 [ 72.109561][ T8593] ? genl_op_from_small+0x23/0x3c0 [ 72.114670][ T8593] ? genl_get_cmd+0x3cf/0x480 [ 72.119459][ T8593] genl_rcv_msg+0x328/0x580 [ 72.123974][ T8593] ? genl_get_cmd+0x480/0x480 [ 72.128660][ T8593] ? nbd_start_device+0xd40/0xd40 [ 72.133689][ T8593] ? lock_release+0x710/0x710 [ 72.138383][ T8593] netlink_rcv_skb+0x153/0x420 [ 72.143152][ T8593] ? genl_get_cmd+0x480/0x480 [ 72.147826][ T8593] ? netlink_ack+0xaa0/0xaa0 [ 72.152483][ T8593] genl_rcv+0x24/0x40 [ 72.156500][ T8593] netlink_unicast+0x533/0x7d0 [ 72.161351][ T8593] ? netlink_attachskb+0x870/0x870 [ 72.166456][ T8593] ? _copy_from_iter_full+0x275/0x850 [ 72.171841][ T8593] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 72.178090][ T8593] ? __phys_addr_symbol+0x2c/0x70 [ 72.183152][ T8593] ? __sanitizer_cov_trace_cmp8+0x1d/0x70 [ 72.188869][ T8593] ? __check_object_size+0x171/0x3f0 [ 72.194158][ T8593] netlink_sendmsg+0x856/0xd90 [ 72.198925][ T8593] ? netlink_unicast+0x7d0/0x7d0 [ 72.203890][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.210169][ T8593] ? netlink_unicast+0x7d0/0x7d0 [ 72.215109][ T8593] sock_sendmsg+0xcf/0x120 [ 72.219554][ T8593] ____sys_sendmsg+0x6e8/0x810 [ 72.224336][ T8593] ? kernel_sendmsg+0x50/0x50 [ 72.229003][ T8593] ? do_recvmmsg+0x6c0/0x6c0 [ 72.233596][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.239864][ T8593] ? netlink_recvmsg+0x826/0xee0 [ 72.244827][ T8593] ___sys_sendmsg+0xf3/0x170 [ 72.249429][ T8593] ? sendmsg_copy_msghdr+0x160/0x160 [ 72.254719][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.260960][ T8593] ? security_socket_recvmsg+0x8f/0xc0 [ 72.266428][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.272772][ T8593] ? __sys_recvfrom+0x2cc/0x3a0 [ 72.277618][ T8593] ? __ia32_sys_send+0x100/0x100 [ 72.282559][ T8593] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 72.288835][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.295098][ T8593] ? __fget_light+0x215/0x280 [ 72.299788][ T8593] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 72.306045][ T8593] __sys_sendmsg+0xe5/0x1b0 [ 72.310547][ T8593] ? __sys_sendmsg_sock+0xb0/0xb0 [ 72.315567][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.321815][ T8593] ? syscall_enter_from_user_mode+0x1d/0x50 [ 72.327708][ T8593] do_syscall_64+0x2d/0x70 [ 72.332146][ T8593] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.338484][ T8593] RIP: 0033:0x440709 [ 72.342370][ T8593] 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 [ 72.361999][ T8593] RSP: 002b:00007ffe8f28ba68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 72.370519][ T8593] RAX: ffffffffffffffda RBX: 000000000001184e RCX: 0000000000440709 [ 72.378506][ T8593] RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000003 [ 72.386469][ T8593] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffe8f28bc08 [ 72.394561][ T8593] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8f28ba7c [ 72.402525][ T8593] R13: 431bde82d7b634db R14: 00000000004ae018 R15: 00000000004004a0 [ 72.410508][ T8593] [ 72.412823][ T8593] Allocated by task 8586: [ 72.417136][ T8593] kasan_save_stack+0x1b/0x40 [ 72.421808][ T8593] ____kasan_kmalloc.constprop.0+0x82/0xa0 [ 72.427611][ T8593] nbd_dev_add+0x44/0x8e0 [ 72.431935][ T8593] nbd_genl_connect+0x59c/0x1560 [ 72.436885][ T8593] genl_family_rcv_msg_doit+0x228/0x320 [ 72.442425][ T8593] genl_rcv_msg+0x328/0x580 [ 72.446921][ T8593] netlink_rcv_skb+0x153/0x420 [ 72.451675][ T8593] genl_rcv+0x24/0x40 [ 72.455670][ T8593] netlink_unicast+0x533/0x7d0 [ 72.460466][ T8593] netlink_sendmsg+0x856/0xd90 [ 72.465251][ T8593] sock_sendmsg+0xcf/0x120 [ 72.469678][ T8593] ____sys_sendmsg+0x6e8/0x810 [ 72.474450][ T8593] ___sys_sendmsg+0xf3/0x170 [ 72.479036][ T8593] __sys_sendmsg+0xe5/0x1b0 [ 72.483533][ T8593] do_syscall_64+0x2d/0x70 [ 72.487964][ T8593] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.493875][ T8593] [ 72.496187][ T8593] Freed by task 8593: [ 72.500184][ T8593] kasan_save_stack+0x1b/0x40 [ 72.504868][ T8593] kasan_set_track+0x1c/0x30 [ 72.509583][ T8593] kasan_set_free_info+0x20/0x30 [ 72.514522][ T8593] ____kasan_slab_free+0xe1/0x110 [ 72.519545][ T8593] slab_free_freelist_hook+0x5d/0x150 [ 72.524917][ T8593] kfree+0xdb/0x3b0 [ 72.528717][ T8593] nbd_put.part.0+0x180/0x1d0 [ 72.533392][ T8593] nbd_config_put+0x6dd/0x8c0 [ 72.538074][ T8593] nbd_genl_connect+0xeb7/0x1560 [ 72.543009][ T8593] genl_family_rcv_msg_doit+0x228/0x320 [ 72.548566][ T8593] genl_rcv_msg+0x328/0x580 [ 72.553074][ T8593] netlink_rcv_skb+0x153/0x420 [ 72.558034][ T8593] genl_rcv+0x24/0x40 [ 72.562013][ T8593] netlink_unicast+0x533/0x7d0 [ 72.566768][ T8593] netlink_sendmsg+0x856/0xd90 [ 72.571524][ T8593] sock_sendmsg+0xcf/0x120 [ 72.575930][ T8593] ____sys_sendmsg+0x6e8/0x810 [ 72.580686][ T8593] ___sys_sendmsg+0xf3/0x170 [ 72.585309][ T8593] __sys_sendmsg+0xe5/0x1b0 [ 72.589855][ T8593] do_syscall_64+0x2d/0x70 [ 72.594278][ T8593] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.600302][ T8593] [ 72.602626][ T8593] The buggy address belongs to the object at ffff888029fbe000 [ 72.602626][ T8593] which belongs to the cache kmalloc-1k of size 1024 [ 72.616678][ T8593] The buggy address is located 416 bytes inside of [ 72.616678][ T8593] 1024-byte region [ffff888029fbe000, ffff888029fbe400) [ 72.630149][ T8593] The buggy address belongs to the page: [ 72.635771][ T8593] page:00000000c886d076 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29fb8 [ 72.646004][ T8593] head:00000000c886d076 order:3 compound_mapcount:0 compound_pincount:0 [ 72.654321][ T8593] flags: 0xfff00000010200(slab|head) [ 72.659614][ T8593] raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c41140 [ 72.668223][ T8593] raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 [ 72.676906][ T8593] page dumped because: kasan: bad access detected [ 72.683319][ T8593] [ 72.685632][ T8593] Memory state around the buggy address: [ 72.691290][ T8593] ffff888029fbe080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.699339][ T8593] ffff888029fbe100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.707404][ T8593] >ffff888029fbe180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.715463][ T8593] ^ [ 72.720563][ T8593] ffff888029fbe200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.728627][ T8593] ffff888029fbe280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 72.736675][ T8593] ================================================================== [ 72.744722][ T8593] Disabling lock debugging due to kernel taint [ 72.751936][ T8593] Kernel panic - not syncing: panic_on_warn set ... [ 72.758551][ T8593] CPU: 1 PID: 8593 Comm: syz-executor700 Tainted: G B 5.11.0-rc7-syzkaller #0 [ 72.768770][ T8593] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.778831][ T8593] Call Trace: [ 72.782146][ T8593] dump_stack+0x107/0x163 [ 72.786497][ T8593] ? refcount_dec_not_one+0x10/0x1e0 [ 72.791800][ T8593] panic+0x306/0x73d [ 72.795717][ T8593] ? __warn_printk+0xf3/0xf3 [ 72.800328][ T8593] ? preempt_schedule_common+0x59/0xc0 [ 72.805798][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.811265][ T8593] ? preempt_schedule_thunk+0x16/0x18 [ 72.816631][ T8593] ? trace_hardirqs_on+0x38/0x1c0 [ 72.821647][ T8593] ? trace_hardirqs_on+0x51/0x1c0 [ 72.826662][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.832067][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.837346][ T8593] end_report+0x58/0x5e [ 72.841539][ T8593] kasan_report.cold+0x67/0xd5 [ 72.846293][ T8593] ? refcount_dec_not_one+0x71/0x1e0 [ 72.851567][ T8593] check_memory_region+0x13d/0x180 [ 72.856682][ T8593] refcount_dec_not_one+0x71/0x1e0 [ 72.861781][ T8593] ? refcount_warn_saturate+0x1e0/0x1e0 [ 72.867315][ T8593] ? nbd_config_put+0x5d0/0x8c0 [ 72.872170][ T8593] refcount_dec_and_mutex_lock+0x19/0x140 [ 72.877879][ T8593] nbd_genl_connect+0xee7/0x1560 [ 72.882811][ T8593] ? nbd_start_device+0xd40/0xd40 [ 72.887830][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 72.894062][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x1b7/0x290 [ 72.901428][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0xaf/0x290 [ 72.908706][ T8593] genl_family_rcv_msg_doit+0x228/0x320 [ 72.914242][ T8593] ? genl_family_rcv_msg_attrs_parse.constprop.0+0x290/0x290 [ 72.921608][ T8593] ? genl_op_from_small+0x23/0x3c0 [ 72.926725][ T8593] ? genl_get_cmd+0x3cf/0x480 [ 72.931408][ T8593] genl_rcv_msg+0x328/0x580 [ 72.935903][ T8593] ? genl_get_cmd+0x480/0x480 [ 72.940584][ T8593] ? nbd_start_device+0xd40/0xd40 [ 72.945599][ T8593] ? lock_release+0x710/0x710 [ 72.950267][ T8593] netlink_rcv_skb+0x153/0x420 [ 72.955033][ T8593] ? genl_get_cmd+0x480/0x480 [ 72.959709][ T8593] ? netlink_ack+0xaa0/0xaa0 [ 72.964301][ T8593] genl_rcv+0x24/0x40 [ 72.968288][ T8593] netlink_unicast+0x533/0x7d0 [ 72.973062][ T8593] ? netlink_attachskb+0x870/0x870 [ 72.978173][ T8593] ? _copy_from_iter_full+0x275/0x850 [ 72.983536][ T8593] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 72.989779][ T8593] ? __phys_addr_symbol+0x2c/0x70 [ 72.994796][ T8593] ? __sanitizer_cov_trace_cmp8+0x1d/0x70 [ 73.000537][ T8593] ? __check_object_size+0x171/0x3f0 [ 73.005841][ T8593] netlink_sendmsg+0x856/0xd90 [ 73.010599][ T8593] ? netlink_unicast+0x7d0/0x7d0 [ 73.015539][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.021770][ T8593] ? netlink_unicast+0x7d0/0x7d0 [ 73.026696][ T8593] sock_sendmsg+0xcf/0x120 [ 73.031106][ T8593] ____sys_sendmsg+0x6e8/0x810 [ 73.035870][ T8593] ? kernel_sendmsg+0x50/0x50 [ 73.040552][ T8593] ? do_recvmmsg+0x6c0/0x6c0 [ 73.045128][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.051359][ T8593] ? netlink_recvmsg+0x826/0xee0 [ 73.056293][ T8593] ___sys_sendmsg+0xf3/0x170 [ 73.060896][ T8593] ? sendmsg_copy_msghdr+0x160/0x160 [ 73.066176][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.072426][ T8593] ? security_socket_recvmsg+0x8f/0xc0 [ 73.077883][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.084111][ T8593] ? __sys_recvfrom+0x2cc/0x3a0 [ 73.088950][ T8593] ? __ia32_sys_send+0x100/0x100 [ 73.093915][ T8593] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 73.100148][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.106399][ T8593] ? __fget_light+0x215/0x280 [ 73.111065][ T8593] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 73.117299][ T8593] __sys_sendmsg+0xe5/0x1b0 [ 73.121798][ T8593] ? __sys_sendmsg_sock+0xb0/0xb0 [ 73.126860][ T8593] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.133114][ T8593] ? syscall_enter_from_user_mode+0x1d/0x50 [ 73.139015][ T8593] do_syscall_64+0x2d/0x70 [ 73.143416][ T8593] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 73.149314][ T8593] RIP: 0033:0x440709 [ 73.153245][ T8593] 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 [ 73.172849][ T8593] RSP: 002b:00007ffe8f28ba68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 73.181250][ T8593] RAX: ffffffffffffffda RBX: 000000000001184e RCX: 0000000000440709 [ 73.189223][ T8593] RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000003 [ 73.197191][ T8593] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffe8f28bc08 [ 73.205162][ T8593] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8f28ba7c [ 73.213117][ T8593] R13: 431bde82d7b634db R14: 00000000004ae018 R15: 00000000004004a0 [ 73.221711][ T8593] Kernel Offset: disabled [ 73.226047][ T8593] Rebooting in 86400 seconds..