rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9039/1:b..l rcu: (detected by 0, t=10502 jiffies, g=33593, q=583 ncpus=2) task:syz-executor state:R running task stack:21032 pid:9039 tgid:9039 ppid:9014 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:xas_find+0xd6/0x970 lib/xarray.c:1399 Code: 48 89 44 24 20 42 80 3c 30 00 74 08 48 89 df e8 90 a3 fe f5 48 89 5c 24 08 48 8b 1b 48 89 df 4c 89 fe e8 9d 6c 94 f5 4c 39 fb <76> 14 e8 33 6a 94 f5 e9 59 07 00 00 e8 29 6a 94 f5 e9 66 07 00 00 RSP: 0018:ffffc90003e674b0 EFLAGS: 00000213 RAX: 0000000000000000 RBX: 00000000000007ba RCX: ffff88804a205a00 RDX: 0000000000000000 RSI: fffffffffffffffe RDI: 00000000000007ba RBP: ffff888058fb4840 R08: ffffffff8c2eeaf3 R09: 1ffffd400027ced8 R10: dffffc0000000000 R11: fffff9400027ced9 R12: 1ffff920007ccebb R13: ffffc90003e675d8 R14: dffffc0000000000 R15: fffffffffffffffe find_get_entry mm/filemap.c:2025 [inline] find_lock_entries+0x26b/0xbc0 mm/filemap.c:2129 shmem_undo_range+0x2d6/0x1820 mm/shmem.c:1107 shmem_truncate_range mm/shmem.c:1237 [inline] shmem_evict_inode+0x29d/0xa80 mm/shmem.c:1365 evict+0x4fb/0x9b0 fs/inode.c:810 __dentry_kill+0x20d/0x630 fs/dcache.c:660 dput+0x19f/0x2b0 fs/dcache.c:902 __fput+0x60b/0x9f0 fs/file_table.c:473 task_work_run+0x253/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9acbf8cdca RSP: 002b:00007ffd82cefa00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f9acbf8cdca RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffd82cefa5c R08: 0000000000000000 R09: 00007ffd82cef767 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000f R13: 00000000000927c0 R14: 0000000000040d7a R15: 00007ffd82cefab0 rcu: rcu_preempt kthread starved for 10490 jiffies! g33593 f0x0 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:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 9558 Comm: syz.1.1317 Not tainted 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bac/0x2d40 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 18 e3 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 c8 de 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 RSP: 0018:ffffc9000b9df760 EFLAGS: 00000246 RAX: ffffffff81b7768d RBX: 1ffff110170e7e91 RCX: 0000000000080000 RDX: ffffc9000c323000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000b9df948 R08: ffffffff81b77658 R09: 1ffffffff20bfc2e R10: dffffc0000000000 R11: fffffbfff20bfc2f R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 00007ff3816bf6c0(0000) GS:ffff888124f93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0f94370c40 CR3: 000000005bc5a000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 kill_bdev block/bdev.c:90 [inline] set_blocksize+0x39b/0x410 block/bdev.c:175 sb_set_blocksize+0xb5/0x180 block/bdev.c:186 ext4_load_super fs/ext4/super.c:5112 [inline] __ext4_fill_super fs/ext4/super.c:5264 [inline] ext4_fill_super+0x21e7/0x67c0 fs/ext4/super.c:5726 get_tree_bdev_flags+0x492/0x5c0 fs/super.c:1636 vfs_get_tree+0x92/0x2b0 fs/super.c:1759 do_new_mount+0x2cf/0xb70 fs/namespace.c:3881 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount+0x38c/0x400 fs/namespace.c:4409 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff38078f90a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ff3816bee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff3816beef0 RCX: 00007ff38078f90a RDX: 0000200000000040 RSI: 0000200000000000 RDI: 00007ff3816beeb0 RBP: 0000200000000040 R08: 00007ff3816beef0 R09: 000000000000019f R10: 000000000000019f R11: 0000000000000246 R12: 0000200000000000 R13: 00007ff3816beeb0 R14: 0000000000000544 R15: 0000200000000100