[ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.91' (ECDSA) to the list of known hosts. 2021/11/30 08:01:06 fuzzer started 2021/11/30 08:01:06 connecting to host at 10.128.0.169:32851 2021/11/30 08:01:06 checking machine... 2021/11/30 08:01:06 checking revisions... 2021/11/30 08:01:06 testing simple program... syzkaller login: [ 76.100249][ T6582] cgroup: Unknown subsys name 'net' [ 76.106858][ T6582] [ 76.109203][ T6582] ========================= [ 76.113676][ T6582] WARNING: held lock freed! [ 76.118150][ T6582] 5.16.0-rc3-next-20211130-syzkaller #0 Not tainted [ 76.124708][ T6582] ------------------------- [ 76.129178][ T6582] syz-executor/6582 is freeing memory ffff88807cd16400-ffff88807cd165ff, with a lock still held there! [ 76.140257][ T6582] ffff88807cd16548 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 [ 76.149983][ T6582] 2 locks held by syz-executor/6582: [ 76.155241][ T6582] #0: ffffffff8bbc50c8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock_and_drain_offline+0xa5/0x900 [ 76.165763][ T6582] #1: ffff88807cd16548 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 [ 76.176039][ T6582] [ 76.176039][ T6582] stack backtrace: [ 76.181918][ T6582] CPU: 1 PID: 6582 Comm: syz-executor Not tainted 5.16.0-rc3-next-20211130-syzkaller #0 [ 76.191656][ T6582] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.201695][ T6582] Call Trace: [ 76.204959][ T6582] [ 76.207883][ T6582] dump_stack_lvl+0xcd/0x134 [ 76.212486][ T6582] debug_check_no_locks_freed.cold+0x9d/0xa9 [ 76.218470][ T6582] ? lockdep_hardirqs_on+0x79/0x100 [ 76.223672][ T6582] slab_free_freelist_hook+0x73/0x1c0 [ 76.229044][ T6582] ? kernfs_put.part.0+0x331/0x540 [ 76.234241][ T6582] kfree+0xe0/0x430 [ 76.238138][ T6582] ? kmem_cache_free+0xba/0x4a0 [ 76.242986][ T6582] ? rwlock_bug.part.0+0x90/0x90 [ 76.248366][ T6582] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 76.254647][ T6582] kernfs_put.part.0+0x331/0x540 [ 76.259683][ T6582] kernfs_put+0x42/0x50 [ 76.263845][ T6582] __kernfs_remove+0x7a3/0xb20 [ 76.268856][ T6582] ? kernfs_next_descendant_post+0x2f0/0x2f0 [ 76.275719][ T6582] ? down_write+0xde/0x150 [ 76.280137][ T6582] ? down_write_killable_nested+0x180/0x180 [ 76.287409][ T6582] kernfs_destroy_root+0x89/0xb0 [ 76.292350][ T6582] cgroup_setup_root+0x3a6/0xad0 [ 76.297290][ T6582] ? rebind_subsystems+0x10e0/0x10e0 [ 76.302578][ T6582] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 76.308911][ T6582] cgroup1_get_tree+0xd33/0x1390 [ 76.313846][ T6582] vfs_get_tree+0x89/0x2f0 [ 76.318284][ T6582] path_mount+0x1320/0x1fa0 [ 76.322873][ T6582] ? kmem_cache_free+0xba/0x4a0 [ 76.327724][ T6582] ? finish_automount+0xaf0/0xaf0 [ 76.332747][ T6582] ? putname+0xfe/0x140 [ 76.336909][ T6582] __x64_sys_mount+0x27f/0x300 [ 76.341679][ T6582] ? copy_mnt_ns+0xae0/0xae0 [ 76.346264][ T6582] ? syscall_enter_from_user_mode+0x21/0x70 [ 76.352157][ T6582] do_syscall_64+0x35/0xb0 [ 76.356576][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.362465][ T6582] RIP: 0033:0x7fb7b2f5101a [ 76.366871][ T6582] Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 76.386573][ T6582] RSP: 002b:00007fffddc41f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 76.395068][ T6582] RAX: ffffffffffffffda RBX: 00007fffddc42128 RCX: 00007fb7b2f5101a [ 76.403119][ T6582] RDX: 00007fb7b2fb3fe2 RSI: 00007fb7b2faa29a RDI: 00007fb7b2fa8d71 [ 76.411094][ T6582] RBP: 00007fb7b2faa29a R08: 00007fb7b2faa3f7 R09: 0000000000000026 [ 76.419054][ T6582] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffddc41fa0 [ 76.427101][ T6582] R13: 00007fffddc42148 R14: 00007fffddc42070 R15: 00007fb7b2faa3f1 [ 76.435069][ T6582] [ 76.439161][ T6582] ================================================================== [ 76.447237][ T6582] BUG: KASAN: use-after-free in up_write+0x3ac/0x470 [ 76.453920][ T6582] Read of size 8 at addr ffff88807cd16540 by task syz-executor/6582 [ 76.461898][ T6582] [ 76.464248][ T6582] CPU: 0 PID: 6582 Comm: syz-executor Not tainted 5.16.0-rc3-next-20211130-syzkaller #0 [ 76.473942][ T6582] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.483975][ T6582] Call Trace: [ 76.487234][ T6582] [ 76.490158][ T6582] dump_stack_lvl+0xcd/0x134 [ 76.494739][ T6582] print_address_description.constprop.0.cold+0xa5/0x3ed [ 76.501762][ T6582] ? up_write+0x3ac/0x470 [ 76.506071][ T6582] ? up_write+0x3ac/0x470 [ 76.510393][ T6582] kasan_report.cold+0x83/0xdf [ 76.515229][ T6582] ? up_write+0x3ac/0x470 [ 76.519539][ T6582] up_write+0x3ac/0x470 [ 76.523685][ T6582] cgroup_setup_root+0x3a6/0xad0 [ 76.528606][ T6582] ? rebind_subsystems+0x10e0/0x10e0 [ 76.533887][ T6582] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 76.540110][ T6582] cgroup1_get_tree+0xd33/0x1390 [ 76.545048][ T6582] vfs_get_tree+0x89/0x2f0 [ 76.549456][ T6582] path_mount+0x1320/0x1fa0 [ 76.553953][ T6582] ? kmem_cache_free+0xba/0x4a0 [ 76.558795][ T6582] ? finish_automount+0xaf0/0xaf0 [ 76.563803][ T6582] ? putname+0xfe/0x140 [ 76.567944][ T6582] __x64_sys_mount+0x27f/0x300 [ 76.572689][ T6582] ? copy_mnt_ns+0xae0/0xae0 [ 76.577257][ T6582] ? syscall_enter_from_user_mode+0x21/0x70 [ 76.583157][ T6582] do_syscall_64+0x35/0xb0 [ 76.587554][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.593556][ T6582] RIP: 0033:0x7fb7b2f5101a [ 76.598042][ T6582] Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 76.617625][ T6582] RSP: 002b:00007fffddc41f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 76.626031][ T6582] RAX: ffffffffffffffda RBX: 00007fffddc42128 RCX: 00007fb7b2f5101a [ 76.633985][ T6582] RDX: 00007fb7b2fb3fe2 RSI: 00007fb7b2faa29a RDI: 00007fb7b2fa8d71 [ 76.641936][ T6582] RBP: 00007fb7b2faa29a R08: 00007fb7b2faa3f7 R09: 0000000000000026 [ 76.649882][ T6582] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffddc41fa0 [ 76.657829][ T6582] R13: 00007fffddc42148 R14: 00007fffddc42070 R15: 00007fb7b2faa3f1 [ 76.665786][ T6582] [ 76.668784][ T6582] [ 76.671085][ T6582] Allocated by task 6582: [ 76.675474][ T6582] kasan_save_stack+0x1e/0x50 [ 76.680141][ T6582] __kasan_kmalloc+0xa9/0xd0 [ 76.684711][ T6582] kernfs_create_root+0x4c/0x410 [ 76.689638][ T6582] cgroup_setup_root+0x243/0xad0 [ 76.694557][ T6582] cgroup1_get_tree+0xd33/0x1390 [ 76.699556][ T6582] vfs_get_tree+0x89/0x2f0 [ 76.703952][ T6582] path_mount+0x1320/0x1fa0 [ 76.708434][ T6582] __x64_sys_mount+0x27f/0x300 [ 76.713312][ T6582] do_syscall_64+0x35/0xb0 [ 76.717884][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.723755][ T6582] [ 76.726057][ T6582] Freed by task 6582: [ 76.730109][ T6582] kasan_save_stack+0x1e/0x50 [ 76.734766][ T6582] kasan_set_track+0x21/0x30 [ 76.739348][ T6582] kasan_set_free_info+0x20/0x30 [ 76.744344][ T6582] __kasan_slab_free+0x103/0x170 [ 76.749262][ T6582] slab_free_freelist_hook+0x8b/0x1c0 [ 76.754615][ T6582] kfree+0xe0/0x430 [ 76.758402][ T6582] kernfs_put.part.0+0x331/0x540 [ 76.763319][ T6582] kernfs_put+0x42/0x50 [ 76.767465][ T6582] __kernfs_remove+0x7a3/0xb20 [ 76.772408][ T6582] kernfs_destroy_root+0x89/0xb0 [ 76.777325][ T6582] cgroup_setup_root+0x3a6/0xad0 [ 76.782242][ T6582] cgroup1_get_tree+0xd33/0x1390 [ 76.787155][ T6582] vfs_get_tree+0x89/0x2f0 [ 76.791553][ T6582] path_mount+0x1320/0x1fa0 [ 76.796038][ T6582] __x64_sys_mount+0x27f/0x300 [ 76.800780][ T6582] do_syscall_64+0x35/0xb0 [ 76.805187][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.811056][ T6582] [ 76.813359][ T6582] The buggy address belongs to the object at ffff88807cd16400 [ 76.813359][ T6582] which belongs to the cache kmalloc-512 of size 512 [ 76.827734][ T6582] The buggy address is located 320 bytes inside of [ 76.827734][ T6582] 512-byte region [ffff88807cd16400, ffff88807cd16600) [ 76.841088][ T6582] The buggy address belongs to the page: [ 76.846692][ T6582] page:ffffea0001f34500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7cd14 [ 76.856828][ T6582] head:ffffea0001f34500 order:2 compound_mapcount:0 compound_pincount:0 [ 76.865141][ T6582] flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) [ 76.873106][ T6582] raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888010c41c80 [ 76.881784][ T6582] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 76.890343][ T6582] page dumped because: kasan: bad access detected [ 76.896728][ T6582] page_owner tracks the page as allocated [ 76.902427][ T6582] page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2975, ts 30760872567, free_ts 27439116275 [ 76.921513][ T6582] get_page_from_freelist+0xa72/0x2f40 [ 76.927043][ T6582] __alloc_pages+0x1b2/0x500 [ 76.931612][ T6582] alloc_pages+0x1a7/0x300 [ 76.936039][ T6582] new_slab+0x261/0x460 [ 76.940173][ T6582] ___slab_alloc+0x798/0xf30 [ 76.944742][ T6582] __slab_alloc.constprop.0+0x4d/0xa0 [ 76.950095][ T6582] kmem_cache_alloc_trace+0x289/0x2c0 [ 76.955470][ T6582] kernfs_fop_open+0x2b9/0xd30 [ 76.960219][ T6582] do_dentry_open+0x4c8/0x1250 [ 76.964962][ T6582] path_openat+0x1cad/0x2750 [ 76.969529][ T6582] do_filp_open+0x1aa/0x400 [ 76.974012][ T6582] do_sys_openat2+0x16d/0x4d0 [ 76.978664][ T6582] __x64_sys_open+0x119/0x1c0 [ 76.983316][ T6582] do_syscall_64+0x35/0xb0 [ 76.987711][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.993591][ T6582] page last free stack trace: [ 76.998338][ T6582] free_pcp_prepare+0x414/0xb60 [ 77.003231][ T6582] free_unref_page+0x19/0x690 [ 77.007902][ T6582] __unfreeze_partials+0x19f/0x1c0 [ 77.013041][ T6582] qlist_free_all+0x5a/0xf0 [ 77.017566][ T6582] kasan_quarantine_reduce+0x180/0x200 [ 77.023105][ T6582] __kasan_slab_alloc+0xa2/0xc0 [ 77.028074][ T6582] kmem_cache_alloc+0x202/0x3a0 [ 77.032915][ T6582] getname_flags.part.0+0x50/0x4f0 [ 77.038008][ T6582] getname_flags+0x9a/0xe0 [ 77.042408][ T6582] user_path_at_empty+0x2b/0x60 [ 77.047367][ T6582] do_readlinkat+0xcd/0x2f0 [ 77.051990][ T6582] __x64_sys_readlinkat+0x93/0xf0 [ 77.056995][ T6582] do_syscall_64+0x35/0xb0 [ 77.061509][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.067389][ T6582] [ 77.069694][ T6582] Memory state around the buggy address: [ 77.075308][ T6582] ffff88807cd16400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.083356][ T6582] ffff88807cd16480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.091400][ T6582] >ffff88807cd16500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.099448][ T6582] ^ [ 77.105594][ T6582] ffff88807cd16580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.113737][ T6582] ffff88807cd16600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 77.121779][ T6582] ================================================================== [ 77.132362][ T6582] Kernel panic - not syncing: panic_on_warn set ... [ 77.138957][ T6582] CPU: 0 PID: 6582 Comm: syz-executor Tainted: G B 5.16.0-rc3-next-20211130-syzkaller #0 [ 77.150068][ T6582] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 77.160122][ T6582] Call Trace: [ 77.163398][ T6582] [ 77.166324][ T6582] dump_stack_lvl+0xcd/0x134 [ 77.170924][ T6582] panic+0x2b0/0x6dd [ 77.174804][ T6582] ? __warn_printk+0xf3/0xf3 [ 77.179381][ T6582] ? preempt_schedule_common+0x59/0xc0 [ 77.184996][ T6582] ? up_write+0x3ac/0x470 [ 77.189307][ T6582] ? preempt_schedule_thunk+0x16/0x18 [ 77.194658][ T6582] ? trace_hardirqs_on+0x38/0x1c0 [ 77.199685][ T6582] ? trace_hardirqs_on+0x51/0x1c0 [ 77.204702][ T6582] ? up_write+0x3ac/0x470 [ 77.209023][ T6582] ? up_write+0x3ac/0x470 [ 77.213343][ T6582] end_report.cold+0x63/0x6f [ 77.217931][ T6582] kasan_report.cold+0x71/0xdf [ 77.222699][ T6582] ? up_write+0x3ac/0x470 [ 77.227028][ T6582] up_write+0x3ac/0x470 [ 77.231172][ T6582] cgroup_setup_root+0x3a6/0xad0 [ 77.236099][ T6582] ? rebind_subsystems+0x10e0/0x10e0 [ 77.241387][ T6582] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 77.247744][ T6582] cgroup1_get_tree+0xd33/0x1390 [ 77.252865][ T6582] vfs_get_tree+0x89/0x2f0 [ 77.257266][ T6582] path_mount+0x1320/0x1fa0 [ 77.261753][ T6582] ? kmem_cache_free+0xba/0x4a0 [ 77.266677][ T6582] ? finish_automount+0xaf0/0xaf0 [ 77.271774][ T6582] ? putname+0xfe/0x140 [ 77.275917][ T6582] __x64_sys_mount+0x27f/0x300 [ 77.280665][ T6582] ? copy_mnt_ns+0xae0/0xae0 [ 77.285366][ T6582] ? syscall_enter_from_user_mode+0x21/0x70 [ 77.291243][ T6582] do_syscall_64+0x35/0xb0 [ 77.295666][ T6582] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.301556][ T6582] RIP: 0033:0x7fb7b2f5101a [ 77.305975][ T6582] Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 77.325572][ T6582] RSP: 002b:00007fffddc41f98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 77.333975][ T6582] RAX: ffffffffffffffda RBX: 00007fffddc42128 RCX: 00007fb7b2f5101a [ 77.341929][ T6582] RDX: 00007fb7b2fb3fe2 RSI: 00007fb7b2faa29a RDI: 00007fb7b2fa8d71 [ 77.349881][ T6582] RBP: 00007fb7b2faa29a R08: 00007fb7b2faa3f7 R09: 0000000000000026 [ 77.357851][ T6582] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffddc41fa0 [ 77.365802][ T6582] R13: 00007fffddc42148 R14: 00007fffddc42070 R15: 00007fb7b2faa3f1 [ 77.373845][ T6582] [ 77.377138][ T6582] Kernel Offset: disabled [ 77.381450][ T6582] Rebooting in 86400 seconds..