======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc7-syzkaller-ge40939bbfc68 #0 Not tainted
------------------------------------------------------
syz-executor.1/7248 is trying to acquire lock:
ffff80008df60dd0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_inc+0x1c/0x40 kernel/jump_label.c:185
but task is already holding lock:
ffff80008e0f3528 (freezer_mutex){+.+.}-{3:3}, at: freezer_css_online+0x50/0x150 kernel/cgroup/legacy_freezer.c:111
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (freezer_mutex){+.+.}-{3:3}:
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
freezer_change_state kernel/cgroup/legacy_freezer.c:389 [inline]
freezer_write+0xc4/0x43c kernel/cgroup/legacy_freezer.c:429
cgroup_file_write+0x258/0x5ac kernel/cgroup/cgroup.c:4071
kernfs_fop_write_iter+0x334/0x48c fs/kernfs/file.c:334
call_write_iter include/linux/fs.h:1868 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x618/0x918 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3113 [inline]
check_prevs_add kernel/locking/lockdep.c:3232 [inline]
validate_chain kernel/locking/lockdep.c:3847 [inline]
__lock_acquire+0x3308/0x7604 kernel/locking/lockdep.c:5088
lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
cpus_read_lock+0x58/0x2a4 kernel/cpu.c:310
static_key_slow_inc+0x1c/0x40 kernel/jump_label.c:185
freezer_css_online+0xbc/0x150 kernel/cgroup/legacy_freezer.c:117
online_css+0xc8/0x2b4 kernel/cgroup/cgroup.c:5491
css_create kernel/cgroup/cgroup.c:5562 [inline]
cgroup_apply_control_enable+0x6d8/0x9ac kernel/cgroup/cgroup.c:3249
cgroup_mkdir+0x9b4/0xd50 kernel/cgroup/cgroup.c:5758
kernfs_iop_mkdir+0x22c/0x3bc fs/kernfs/dir.c:1219
vfs_mkdir+0x240/0x3a8 fs/namei.c:4115
do_mkdirat+0x20c/0x610 fs/namei.c:4138
__do_sys_mkdirat fs/namei.c:4153 [inline]
__se_sys_mkdirat fs/namei.c:4151 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4151
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(freezer_mutex);
lock(cpu_hotplug_lock);
lock(freezer_mutex);
rlock(cpu_hotplug_lock);
*** DEADLOCK ***
4 locks held by syz-executor.1/7248:
#0: ffff0000dde24460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:394
#1: ffff00010953f3f0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:810 [inline]
#1: ffff00010953f3f0 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: filename_create+0x204/0x468 fs/namei.c:3884
#2: ffff80008e0e8ca8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:370 [inline]
#2: ffff80008e0e8ca8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf8/0x258 kernel/cgroup/cgroup.c:1683
#3: ffff80008e0f3528 (freezer_mutex){+.+.}-{3:3}, at: freezer_css_online+0x50/0x150 kernel/cgroup/legacy_freezer.c:111
stack backtrace:
CPU: 1 PID: 7248 Comm: syz-executor.1 Not tainted 6.4.0-rc7-syzkaller-ge40939bbfc68 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
dump_stack+0x1c/0x28 lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2066
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2188
check_prev_add kernel/locking/lockdep.c:3113 [inline]
check_prevs_add kernel/locking/lockdep.c:3232 [inline]
validate_chain kernel/locking/lockdep.c:3847 [inline]
__lock_acquire+0x3308/0x7604 kernel/locking/lockdep.c:5088
lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
cpus_read_lock+0x58/0x2a4 kernel/cpu.c:310
static_key_slow_inc+0x1c/0x40 kernel/jump_label.c:185
freezer_css_online+0xbc/0x150 kernel/cgroup/legacy_freezer.c:117
online_css+0xc8/0x2b4 kernel/cgroup/cgroup.c:5491
css_create kernel/cgroup/cgroup.c:5562 [inline]
cgroup_apply_control_enable+0x6d8/0x9ac kernel/cgroup/cgroup.c:3249
cgroup_mkdir+0x9b4/0xd50 kernel/cgroup/cgroup.c:5758
kernfs_iop_mkdir+0x22c/0x3bc fs/kernfs/dir.c:1219
vfs_mkdir+0x240/0x3a8 fs/namei.c:4115
do_mkdirat+0x20c/0x610 fs/namei.c:4138
__do_sys_mkdirat fs/namei.c:4153 [inline]
__se_sys_mkdirat fs/namei.c:4151 [inline]
__arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4151
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591