rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10002 jiffies, g=2561, q=38346 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10000 (4294956607-4294946607), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10000 jiffies! g2561 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:14448 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x691/0x970 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xab/0x110 kernel/sched/core.c:6778 schedule_timeout+0x117/0x190 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x17a/0x590 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x1c/0x110 kernel/rcu/tree.c:1830 kthread+0xe9/0x100 kernel/kthread.c:388 ret_from_fork+0x32/0x40 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 3486 Comm: syz.3.16 Not tainted 6.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:exfat_clear_bitmap+0x5c/0xe0 fs/exfat/balloc.c:160 Code: 03 41 0f b6 4e 14 48 d3 e8 41 8b 4e 18 8d 0c cd ff ff ff ff 21 d9 48 63 c9 49 8b 77 60 48 8b 34 c6 48 8b 76 28 f0 48 0f b3 0e <49> 8b 4f 60 48 8b 3c c1 0f b6 f2 e8 84 e9 ff ff 41 f6 87 b4 01 00 RSP: 0018:ffffc90001d67a28 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000000000009 RCX: 0000000000000009 RDX: 0000000000000000 RSI: ffff88816c867000 RDI: ffff88817e390168 RBP: ffff8881033db000 R08: 000000000000000c R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8881033db000 R15: ffff8881033da000 FS: 00007fb47bb046c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff79bb7440 CR3: 0000000109ba4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __exfat_free_cluster+0x133/0x200 fs/exfat/fatent.c:213 exfat_free_cluster+0x35/0x60 fs/exfat/fatent.c:232 __exfat_truncate+0x1ac/0x1f0 fs/exfat/file.c:229 exfat_truncate+0x42/0xd0 fs/exfat/file.c:253 exfat_setattr+0x445/0x490 fs/exfat/file.c:355 notify_change+0x2e9/0x360 fs/attr.c:499 do_truncate+0xe1/0x120 fs/open.c:66 handle_truncate fs/namei.c:3280 [inline] do_open fs/namei.c:3626 [inline] path_openat+0xc97/0xd80 fs/namei.c:3779 do_filp_open+0xac/0x150 fs/namei.c:3809 do_sys_openat2+0x7e/0xe0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1528 [inline] __se_sys_creat fs/open.c:1522 [inline] __x64_sys_creat+0x46/0x70 fs/open.c:1522 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4d/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fb47ad85d29 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:00007fb47bb04038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fb47af75fa0 RCX: 00007fb47ad85d29 RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000020000200 RBP: 00007fb47ae01aa8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb47af75fa0 R15: 00007ffd8c2ecb58