[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.140' (ECDSA) to the list of known hosts. 2021/11/29 08:03:02 fuzzer started 2021/11/29 08:03:02 connecting to host at 10.128.0.169:35737 2021/11/29 08:03:02 checking machine... 2021/11/29 08:03:02 checking revisions... 2021/11/29 08:03:02 testing simple program... syzkaller login: [ 76.260301][ T6535] cgroup: Unknown subsys name 'net' [ 76.266763][ T6535] [ 76.269106][ T6535] ========================= [ 76.273697][ T6535] WARNING: held lock freed! [ 76.278203][ T6535] 5.16.0-rc2-next-20211129-syzkaller #0 Not tainted [ 76.284915][ T6535] ------------------------- [ 76.289419][ T6535] syz-executor/6535 is freeing memory ffff8881472c5400-ffff8881472c55ff, with a lock still held there! [ 76.300533][ T6535] ffff8881472c5548 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 [ 76.310470][ T6535] 2 locks held by syz-executor/6535: [ 76.315733][ T6535] #0: ffffffff8bbc5d08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock_and_drain_offline+0xa5/0x900 [ 76.326387][ T6535] #1: ffff8881472c5548 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 [ 76.336653][ T6535] [ 76.336653][ T6535] stack backtrace: [ 76.342616][ T6535] CPU: 0 PID: 6535 Comm: syz-executor Not tainted 5.16.0-rc2-next-20211129-syzkaller #0 [ 76.352318][ T6535] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.362381][ T6535] Call Trace: [ 76.365653][ T6535] [ 76.368592][ T6535] dump_stack_lvl+0xcd/0x134 [ 76.373550][ T6535] debug_check_no_locks_freed.cold+0x9d/0xa9 [ 76.379581][ T6535] ? lockdep_hardirqs_on+0x79/0x100 [ 76.384818][ T6535] slab_free_freelist_hook+0x73/0x1c0 [ 76.390208][ T6535] ? kernfs_put.part.0+0x331/0x540 [ 76.395327][ T6535] kfree+0xe0/0x430 [ 76.399142][ T6535] ? kmem_cache_free+0xba/0x4a0 [ 76.404036][ T6535] ? rwlock_bug.part.0+0x90/0x90 [ 76.409085][ T6535] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 76.415338][ T6535] kernfs_put.part.0+0x331/0x540 [ 76.420292][ T6535] kernfs_put+0x42/0x50 [ 76.424553][ T6535] __kernfs_remove+0x7a3/0xb20 [ 76.429329][ T6535] ? kernfs_next_descendant_post+0x2f0/0x2f0 [ 76.435310][ T6535] ? down_write+0xde/0x150 [ 76.439753][ T6535] ? down_write_killable_nested+0x180/0x180 [ 76.445658][ T6535] kernfs_destroy_root+0x89/0xb0 [ 76.450894][ T6535] cgroup_setup_root+0x3a6/0xad0 [ 76.455869][ T6535] ? rebind_subsystems+0x10e0/0x10e0 [ 76.461164][ T6535] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 76.467431][ T6535] cgroup1_get_tree+0xd33/0x1390 [ 76.472376][ T6535] vfs_get_tree+0x89/0x2f0 [ 76.476792][ T6535] path_mount+0x1320/0x1fa0 [ 76.481302][ T6535] ? kmem_cache_free+0xba/0x4a0 [ 76.486157][ T6535] ? finish_automount+0xaf0/0xaf0 [ 76.491193][ T6535] ? putname+0xfe/0x140 [ 76.495353][ T6535] __x64_sys_mount+0x27f/0x300 [ 76.500120][ T6535] ? copy_mnt_ns+0xae0/0xae0 [ 76.504971][ T6535] ? syscall_enter_from_user_mode+0x21/0x70 [ 76.510899][ T6535] do_syscall_64+0x35/0xb0 [ 76.515408][ T6535] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.521306][ T6535] RIP: 0033:0x7fd22140301a [ 76.525723][ T6535] 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 [ 76.545507][ T6535] RSP: 002b:00007ffc25f03ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 76.553918][ T6535] RAX: ffffffffffffffda RBX: 00007ffc25f04038 RCX: 00007fd22140301a [ 76.561884][ T6535] RDX: 00007fd221465fd6 RSI: 00007fd22145c29a RDI: 00007fd22145ad71 [ 76.570111][ T6535] RBP: 00007fd22145c29a R08: 00007fd22145c3f7 R09: 0000000000000026 [ 76.578074][ T6535] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc25f03eb0 [ 76.586052][ T6535] R13: 00007ffc25f04058 R14: 00007ffc25f03f80 R15: 00007fd22145c3f1 [ 76.594045][ T6535] [ 76.597398][ T6535] ================================================================== [ 76.605471][ T6535] BUG: KASAN: use-after-free in up_write+0x3ac/0x470 [ 76.612166][ T6535] Read of size 8 at addr ffff8881472c5540 by task syz-executor/6535 [ 76.620147][ T6535] [ 76.622467][ T6535] CPU: 1 PID: 6535 Comm: syz-executor Not tainted 5.16.0-rc2-next-20211129-syzkaller #0 [ 76.632179][ T6535] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.642226][ T6535] Call Trace: [ 76.645504][ T6535] [ 76.648428][ T6535] dump_stack_lvl+0xcd/0x134 [ 76.653022][ T6535] print_address_description.constprop.0.cold+0xa5/0x3ed [ 76.660048][ T6535] ? up_write+0x3ac/0x470 [ 76.664375][ T6535] ? up_write+0x3ac/0x470 [ 76.668801][ T6535] kasan_report.cold+0x83/0xdf [ 76.673581][ T6535] ? up_write+0x3ac/0x470 [ 76.677929][ T6535] up_write+0x3ac/0x470 [ 76.682087][ T6535] cgroup_setup_root+0x3a6/0xad0 [ 76.687043][ T6535] ? rebind_subsystems+0x10e0/0x10e0 [ 76.692791][ T6535] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 76.699040][ T6535] cgroup1_get_tree+0xd33/0x1390 [ 76.704181][ T6535] vfs_get_tree+0x89/0x2f0 [ 76.708693][ T6535] path_mount+0x1320/0x1fa0 [ 76.713283][ T6535] ? kmem_cache_free+0xba/0x4a0 [ 76.718143][ T6535] ? finish_automount+0xaf0/0xaf0 [ 76.723172][ T6535] ? putname+0xfe/0x140 [ 76.727448][ T6535] __x64_sys_mount+0x27f/0x300 [ 76.732214][ T6535] ? copy_mnt_ns+0xae0/0xae0 [ 76.736804][ T6535] ? syscall_enter_from_user_mode+0x21/0x70 [ 76.742699][ T6535] do_syscall_64+0x35/0xb0 [ 76.747138][ T6535] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.753035][ T6535] RIP: 0033:0x7fd22140301a [ 76.757453][ T6535] 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 [ 76.777234][ T6535] RSP: 002b:00007ffc25f03ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 76.785649][ T6535] RAX: ffffffffffffffda RBX: 00007ffc25f04038 RCX: 00007fd22140301a [ 76.793815][ T6535] RDX: 00007fd221465fd6 RSI: 00007fd22145c29a RDI: 00007fd22145ad71 [ 76.801949][ T6535] RBP: 00007fd22145c29a R08: 00007fd22145c3f7 R09: 0000000000000026 [ 76.809915][ T6535] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc25f03eb0 [ 76.817985][ T6535] R13: 00007ffc25f04058 R14: 00007ffc25f03f80 R15: 00007fd22145c3f1 [ 76.825963][ T6535] [ 76.829059][ T6535] [ 76.831384][ T6535] Allocated by task 6535: [ 76.835698][ T6535] kasan_save_stack+0x1e/0x50 [ 76.840467][ T6535] __kasan_kmalloc+0xa9/0xd0 [ 76.845163][ T6535] kernfs_create_root+0x4c/0x410 [ 76.850270][ T6535] cgroup_setup_root+0x243/0xad0 [ 76.855557][ T6535] cgroup1_get_tree+0xd33/0x1390 [ 76.860668][ T6535] vfs_get_tree+0x89/0x2f0 [ 76.865124][ T6535] path_mount+0x1320/0x1fa0 [ 76.869643][ T6535] __x64_sys_mount+0x27f/0x300 [ 76.874519][ T6535] do_syscall_64+0x35/0xb0 [ 76.878937][ T6535] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.884830][ T6535] [ 76.887158][ T6535] Freed by task 6535: [ 76.891141][ T6535] kasan_save_stack+0x1e/0x50 [ 76.895844][ T6535] kasan_set_track+0x21/0x30 [ 76.900471][ T6535] kasan_set_free_info+0x20/0x30 [ 76.905444][ T6535] __kasan_slab_free+0x103/0x170 [ 76.910485][ T6535] slab_free_freelist_hook+0x8b/0x1c0 [ 76.915868][ T6535] kfree+0xe0/0x430 [ 76.919780][ T6535] kernfs_put.part.0+0x331/0x540 [ 76.924733][ T6535] kernfs_put+0x42/0x50 [ 76.928907][ T6535] __kernfs_remove+0x7a3/0xb20 [ 76.933694][ T6535] kernfs_destroy_root+0x89/0xb0 [ 76.938645][ T6535] cgroup_setup_root+0x3a6/0xad0 [ 76.943768][ T6535] cgroup1_get_tree+0xd33/0x1390 [ 76.948723][ T6535] vfs_get_tree+0x89/0x2f0 [ 76.953239][ T6535] path_mount+0x1320/0x1fa0 [ 76.957743][ T6535] __x64_sys_mount+0x27f/0x300 [ 76.962502][ T6535] do_syscall_64+0x35/0xb0 [ 76.966916][ T6535] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 76.972806][ T6535] [ 76.975117][ T6535] The buggy address belongs to the object at ffff8881472c5400 [ 76.975117][ T6535] which belongs to the cache kmalloc-512 of size 512 [ 76.989173][ T6535] The buggy address is located 320 bytes inside of [ 76.989173][ T6535] 512-byte region [ffff8881472c5400, ffff8881472c5600) [ 77.002439][ T6535] The buggy address belongs to the page: [ 77.008145][ T6535] page:ffffea00051cb100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1472c4 [ 77.018488][ T6535] head:ffffea00051cb100 order:2 compound_mapcount:0 compound_pincount:0 [ 77.026816][ T6535] flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) [ 77.034882][ T6535] raw: 057ff00000010200 0000000000000000 dead000000000001 ffff888010c41c80 [ 77.043459][ T6535] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 77.052025][ T6535] page dumped because: kasan: bad access detected [ 77.058420][ T6535] page_owner tracks the page as allocated [ 77.064116][ T6535] page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, ts 8095160016, free_ts 0 [ 77.079917][ T6535] get_page_from_freelist+0xa72/0x2f40 [ 77.085378][ T6535] __alloc_pages+0x1b2/0x500 [ 77.090053][ T6535] alloc_page_interleave+0x1e/0x200 [ 77.095338][ T6535] alloc_pages+0x29f/0x300 [ 77.099755][ T6535] new_slab+0x261/0x460 [ 77.103910][ T6535] ___slab_alloc+0x798/0xf30 [ 77.108509][ T6535] __slab_alloc.constprop.0+0x4d/0xa0 [ 77.113880][ T6535] kmem_cache_alloc_node_trace+0x116/0x310 [ 77.119683][ T6535] iolatency_pd_alloc+0xb8/0x1b0 [ 77.124616][ T6535] blkcg_activate_policy+0x232/0xc00 [ 77.129897][ T6535] blk_iolatency_init+0x1aa/0x380 [ 77.135197][ T6535] blkcg_init_queue+0x194/0x780 [ 77.140059][ T6535] blk_alloc_queue+0x44c/0x620 [ 77.144822][ T6535] __blk_mq_alloc_disk+0x4c/0x160 [ 77.149840][ T6535] loop_add+0x339/0x900 [ 77.154006][ T6535] loop_init+0x1f4/0x216 [ 77.158243][ T6535] page_owner free stack trace missing [ 77.163592][ T6535] [ 77.165920][ T6535] Memory state around the buggy address: [ 77.171533][ T6535] ffff8881472c5400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.179617][ T6535] ffff8881472c5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.187668][ T6535] >ffff8881472c5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.195714][ T6535] ^ [ 77.202026][ T6535] ffff8881472c5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 77.210078][ T6535] ffff8881472c5600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 77.218443][ T6535] ================================================================== [ 77.229093][ T6535] Kernel panic - not syncing: panic_on_warn set ... [ 77.235715][ T6535] CPU: 0 PID: 6535 Comm: syz-executor Tainted: G B 5.16.0-rc2-next-20211129-syzkaller #0 [ 77.247007][ T6535] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 77.257070][ T6535] Call Trace: [ 77.260397][ T6535] [ 77.263382][ T6535] dump_stack_lvl+0xcd/0x134 [ 77.268023][ T6535] panic+0x2b0/0x6dd [ 77.272025][ T6535] ? __warn_printk+0xf3/0xf3 [ 77.276644][ T6535] ? preempt_schedule_common+0x59/0xc0 [ 77.282523][ T6535] ? up_write+0x3ac/0x470 [ 77.286881][ T6535] ? preempt_schedule_thunk+0x16/0x18 [ 77.292254][ T6535] ? trace_hardirqs_on+0x38/0x1c0 [ 77.297356][ T6535] ? trace_hardirqs_on+0x51/0x1c0 [ 77.302379][ T6535] ? up_write+0x3ac/0x470 [ 77.306723][ T6535] ? up_write+0x3ac/0x470 [ 77.311049][ T6535] end_report.cold+0x63/0x6f [ 77.315647][ T6535] kasan_report.cold+0x71/0xdf [ 77.320438][ T6535] ? up_write+0x3ac/0x470 [ 77.324846][ T6535] up_write+0x3ac/0x470 [ 77.328998][ T6535] cgroup_setup_root+0x3a6/0xad0 [ 77.333940][ T6535] ? rebind_subsystems+0x10e0/0x10e0 [ 77.339223][ T6535] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 77.345462][ T6535] cgroup1_get_tree+0xd33/0x1390 [ 77.350411][ T6535] vfs_get_tree+0x89/0x2f0 [ 77.354826][ T6535] path_mount+0x1320/0x1fa0 [ 77.359342][ T6535] ? kmem_cache_free+0xba/0x4a0 [ 77.364207][ T6535] ? finish_automount+0xaf0/0xaf0 [ 77.369420][ T6535] ? putname+0xfe/0x140 [ 77.373587][ T6535] __x64_sys_mount+0x27f/0x300 [ 77.378383][ T6535] ? copy_mnt_ns+0xae0/0xae0 [ 77.382969][ T6535] ? syscall_enter_from_user_mode+0x21/0x70 [ 77.388897][ T6535] do_syscall_64+0x35/0xb0 [ 77.393406][ T6535] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.399468][ T6535] RIP: 0033:0x7fd22140301a [ 77.404055][ T6535] 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 [ 77.423837][ T6535] RSP: 002b:00007ffc25f03ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 77.433025][ T6535] RAX: ffffffffffffffda RBX: 00007ffc25f04038 RCX: 00007fd22140301a [ 77.440999][ T6535] RDX: 00007fd221465fd6 RSI: 00007fd22145c29a RDI: 00007fd22145ad71 [ 77.448970][ T6535] RBP: 00007fd22145c29a R08: 00007fd22145c3f7 R09: 0000000000000026 [ 77.456927][ T6535] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc25f03eb0 [ 77.465003][ T6535] R13: 00007ffc25f04058 R14: 00007ffc25f03f80 R15: 00007fd22145c3f1 [ 77.473067][ T6535] [ 77.476396][ T6535] Kernel Offset: disabled [ 77.480793][ T6535] Rebooting in 86400 seconds..