BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 6655, name: syz.0.17 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 5 locks held by syz.0.17/6655: #0: ffff88802f549528 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232 #1: ffff88803400a488 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline] #1: ffff88803400a488 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #2: ffff8880341a8c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #3: ffffffff8d3e1658 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:393 [inline] #3: ffffffff8d3e1658 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x13c/0x230 kernel/cgroup/cgroup.c:1735 #4: ffffffff8d3e16f8 (css_set_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #4: ffffffff8d3e16f8 (css_set_lock){+.+.}-{3:3}, at: cgroup_do_freeze kernel/cgroup/freezer.c:182 [inline] #4: ffffffff8d3e16f8 (css_set_lock){+.+.}-{3:3}, at: cgroup_freeze+0x3f8/0x1010 kernel/cgroup/freezer.c:311 irq event stamp: 1746 hardirqs last enabled at (1745): [] native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] hardirqs last enabled at (1745): [] arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] hardirqs last enabled at (1745): [] arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline] hardirqs last enabled at (1745): [] seqcount_lockdep_reader_access+0x123/0x1c0 include/linux/seqlock.h:74 hardirqs last disabled at (1746): [] cgroup_do_freeze kernel/cgroup/freezer.c:181 [inline] hardirqs last disabled at (1746): [] cgroup_freeze+0x3ec/0x1010 kernel/cgroup/freezer.c:311 softirqs last enabled at (1174): [] __local_bh_enable_ip+0x1b3/0x2e0 kernel/softirq.c:305 softirqs last disabled at (1168): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (1168): [] spin_lock_bh include/linux/spinlock_rt.h:87 [inline] softirqs last disabled at (1168): [] cgroup_idr_replace kernel/cgroup/cgroup.c:382 [inline] softirqs last disabled at (1168): [] css_create kernel/cgroup/cgroup.c:5821 [inline] softirqs last disabled at (1168): [] cgroup_apply_control_enable+0x750/0xab0 kernel/cgroup/cgroup.c:3391 CPU: 0 UID: 0 PID: 6655 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 __might_resched+0x44b/0x5d0 kernel/sched/core.c:8925 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline] rt_spin_lock+0xc7/0x3e0 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:44 [inline] cgroup_do_freeze kernel/cgroup/freezer.c:182 [inline] cgroup_freeze+0x3f8/0x1010 kernel/cgroup/freezer.c:311 cgroup_freeze_write+0x156/0x1c0 kernel/cgroup/cgroup.c:4174 cgroup_file_write+0x39b/0x740 kernel/cgroup/cgroup.c:4312 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7b9b6eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd7b91d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd7b9dc5fa0 RCX: 00007fd7b9b6eec9 RDX: 0000000000000012 RSI: 0000200000000200 RDI: 0000000000000004 RBP: 00007fd7b9bf1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7b9dc6038 R14: 00007fd7b9dc5fa0 R15: 00007ffc8928b4f8