cgroup: Unknown subsys name 'net' ========================= WARNING: held lock freed! 5.16.0-rc3-next-20211201-syzkaller #0 Not tainted ------------------------- syz-executor/6551 is freeing memory ffff88814ada7c00-ffff88814ada7dff, with a lock still held there! ffff88814ada7d48 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove fs/kernfs/dir.c:1396 [inline] ffff88814ada7d48 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 fs/kernfs/dir.c:964 2 locks held by syz-executor/6551: #0: ffffffff8bbc4e48 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock_and_drain_offline+0xa5/0x900 kernel/cgroup/cgroup.c:2998 #1: ffff88814ada7d48 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove fs/kernfs/dir.c:1396 [inline] #1: ffff88814ada7d48 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_destroy_root+0x81/0xb0 fs/kernfs/dir.c:964 stack backtrace: CPU: 1 PID: 6551 Comm: syz-executor Not tainted 5.16.0-rc3-next-20211201-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_freed_lock_bug kernel/locking/lockdep.c:6388 [inline] debug_check_no_locks_freed.cold+0x9d/0xa9 kernel/locking/lockdep.c:6421 slab_free_hook mm/slub.c:1695 [inline] slab_free_freelist_hook+0x73/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xe0/0x430 mm/slub.c:4561 kernfs_put.part.0+0x331/0x540 fs/kernfs/dir.c:548 kernfs_put+0x42/0x50 fs/kernfs/dir.c:513 __kernfs_remove+0x7a3/0xb20 fs/kernfs/dir.c:1382 kernfs_remove fs/kernfs/dir.c:1397 [inline] kernfs_destroy_root+0x89/0xb0 fs/kernfs/dir.c:964 cgroup_setup_root+0x3a6/0xad0 kernel/cgroup/cgroup.c:2077 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1194 [inline] cgroup1_get_tree+0xd33/0x1390 kernel/cgroup/cgroup-v1.c:1211 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:3004 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3334 do_mount fs/namespace.c:3347 [inline] __do_sys_mount fs/namespace.c:3555 [inline] __se_sys_mount fs/namespace.c:3532 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3532 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5e6dd8401a 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 RSP: 002b:00007ffee84fa7e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffee84fa978 RCX: 00007f5e6dd8401a RDX: 00007f5e6dde6fe2 RSI: 00007f5e6dddd29a RDI: 00007f5e6dddbd71 RBP: 00007f5e6dddd29a R08: 00007f5e6dddd3f7 R09: 0000000000000026 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee84fa7f0 R13: 00007ffee84fa998 R14: 00007ffee84fa8c0 R15: 00007f5e6dddd3f1 ================================================================== BUG: KASAN: use-after-free in __up_write kernel/locking/rwsem.c:1318 [inline] BUG: KASAN: use-after-free in up_write+0x3ac/0x470 kernel/locking/rwsem.c:1576 Read of size 8 at addr ffff88814ada7d40 by task syz-executor/6551 CPU: 0 PID: 6551 Comm: syz-executor Not tainted 5.16.0-rc3-next-20211201-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xa5/0x3ed mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 __up_write kernel/locking/rwsem.c:1318 [inline] up_write+0x3ac/0x470 kernel/locking/rwsem.c:1576 cgroup_setup_root+0x3a6/0xad0 kernel/cgroup/cgroup.c:2077 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1194 [inline] cgroup1_get_tree+0xd33/0x1390 kernel/cgroup/cgroup-v1.c:1211 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:3004 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3334 do_mount fs/namespace.c:3347 [inline] __do_sys_mount fs/namespace.c:3555 [inline] __se_sys_mount fs/namespace.c:3532 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3532 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5e6dd8401a 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 RSP: 002b:00007ffee84fa7e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffee84fa978 RCX: 00007f5e6dd8401a RDX: 00007f5e6dde6fe2 RSI: 00007f5e6dddd29a RDI: 00007f5e6dddbd71 RBP: 00007f5e6dddd29a R08: 00007f5e6dddd3f7 R09: 0000000000000026 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee84fa7f0 R13: 00007ffee84fa998 R14: 00007ffee84fa8c0 R15: 00007f5e6dddd3f1 Allocated by task 6551: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:724 [inline] kernfs_create_root+0x4c/0x410 fs/kernfs/dir.c:913 cgroup_setup_root+0x243/0xad0 kernel/cgroup/cgroup.c:2018 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1194 [inline] cgroup1_get_tree+0xd33/0x1390 kernel/cgroup/cgroup-v1.c:1211 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:3004 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3334 do_mount fs/namespace.c:3347 [inline] __do_sys_mount fs/namespace.c:3555 [inline] __se_sys_mount fs/namespace.c:3532 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3532 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 6551: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0x103/0x170 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xe0/0x430 mm/slub.c:4561 kernfs_put.part.0+0x331/0x540 fs/kernfs/dir.c:548 kernfs_put+0x42/0x50 fs/kernfs/dir.c:513 __kernfs_remove+0x7a3/0xb20 fs/kernfs/dir.c:1382 kernfs_remove fs/kernfs/dir.c:1397 [inline] kernfs_destroy_root+0x89/0xb0 fs/kernfs/dir.c:964 cgroup_setup_root+0x3a6/0xad0 kernel/cgroup/cgroup.c:2077 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1194 [inline] cgroup1_get_tree+0xd33/0x1390 kernel/cgroup/cgroup-v1.c:1211 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:3004 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3334 do_mount fs/namespace.c:3347 [inline] __do_sys_mount fs/namespace.c:3555 [inline] __se_sys_mount fs/namespace.c:3532 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3532 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88814ada7c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 320 bytes inside of 512-byte region [ffff88814ada7c00, ffff88814ada7e00) The buggy address belongs to the page: page:ffffea00052b6900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14ada4 head:ffffea00052b6900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 ffffea000525c600 dead000000000002 ffff888010c41c80 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 15332351958, free_ts 0 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0xa72/0x2f40 mm/page_alloc.c:4164 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5376 alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2037 alloc_pages+0x29f/0x300 mm/mempolicy.c:2188 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x261/0x460 mm/slub.c:1993 ___slab_alloc+0x798/0xf30 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4956 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1127 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet6_netconf_notify_devconf+0xa0/0x1e0 net/ipv6/addrconf.c:584 __addrconf_sysctl_register+0x269/0x3d0 net/ipv6/addrconf.c:7041 addrconf_sysctl_register net/ipv6/addrconf.c:7078 [inline] addrconf_sysctl_register+0x139/0x1d0 net/ipv6/addrconf.c:7067 ipv6_add_dev+0x96d/0x1160 net/ipv6/addrconf.c:455 addrconf_notify+0x60e/0x1ba0 net/ipv6/addrconf.c:3510 call_netdevice_notifier net/core/dev.c:1619 [inline] call_netdevice_register_notifiers net/core/dev.c:1627 [inline] call_netdevice_register_net_notifiers+0xdd/0x2b0 net/core/dev.c:1657 register_netdevice_notifier+0xf5/0x260 net/core/dev.c:1708 page_owner free stack trace missing Memory state around the buggy address: ffff88814ada7c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814ada7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88814ada7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88814ada7d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814ada7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================