Kernel bug: INFO: rcu detected stall in ext4_file_mmap_prepare
Subsystem: ext4
Status: open

Crash report:
sched: DL replenish lagged too much
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=3aa4/1/0x4000000000000000 softirq=15601/15602 fqs=59
rcu: 	(detected by 0, t=10505 jiffies, g=10297, q=397 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6042 Comm: sed Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__lock_acquire+0x870/0xd20 kernel/locking/lockdep.c:5232
Code: f0 41 89 cf 41 c1 c7 13 29 ce 41 31 f7 01 c1 44 29 f8 44 01 f9 41 c1 c7 04 41 31 c7 49 c1 e7 20 49 09 cf 83 3d e4 f0 26 0e 00 <0f> 85 36 02 00 00 48 83 7c 24 28 00 0f 84 bc 01 00 00 41 8b 46 f8
RSP: 0018:ffffc90000a08b70 EFLAGS: 00000046
RAX: 00000000d6871fb1 RBX: 0000000000000003 RCX: 0000000079909773
RDX: 00000000001caf3d RSI: 00000000afae91f8 RDI: ffff88802c3c3c80
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81adbfa2
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: 0000000000000073
R13: ffff88802c3c47b0 R14: ffff88802c3c4828 R15: 4346289379909773
FS:  0000000000000000(0000) GS:ffff888125ae0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc34ea224e8 CR3: 00000000720e8000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1781 [inline]
 __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 db e5 40 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> f3 7c 09 f6 65 8b 05 ac 68 3d 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90002ef6fa0 EFLAGS: 00000206
RAX: c40c4dc7bc3a9000 RBX: 0000000000000a02 RCX: c40c4dc7bc3a9000
RDX: 0000000000000007 RSI: ffffffff8dbc0fba RDI: 0000000000000001
RBP: ffffc90002ef7028 R08: ffffffff8fc43c37 R09: 1ffffffff1f88786
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: dffffc0000000000
R13: 0000000000000d40 R14: ffffffff8eae95b0 R15: 1ffff920005dedf4
 stack_depot_save_flags+0x41b/0x860 lib/stackdepot.c:720
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4927 [inline]
 slab_alloc_node mm/slub.c:5226 [inline]
 kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5233
 journal_alloc_journal_head fs/jbd2/journal.c:2826 [inline]
 jbd2_journal_add_journal_head+0x95/0x4b0 fs/jbd2/journal.c:2894
 jbd2_journal_get_write_access+0x1c9/0x230 fs/jbd2/transaction.c:1237
 __ext4_journal_get_write_access+0x1c3/0x570 fs/ext4/ext4_jbd2.c:242
 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6326
 __ext4_mark_inode_dirty+0x15b/0x700 fs/ext4/inode.c:6501
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6538
 __mark_inode_dirty+0x2ec/0xe10 fs/fs-writeback.c:2567
 generic_update_time fs/inode.c:2087 [inline]
 inode_update_time fs/inode.c:2100 [inline]
 touch_atime+0x59b/0x6d0 fs/inode.c:2172
 file_accessed include/linux/fs.h:2675 [inline]
 ext4_file_mmap_prepare+0x24d/0x440 fs/ext4/file.c:828
 vfs_mmap_prepare include/linux/fs.h:2412 [inline]
 call_mmap_prepare mm/vma.c:2593 [inline]
 __mmap_region mm/vma.c:2671 [inline]
 mmap_region+0xb38/0x1c70 mm/vma.c:2764
 do_mmap+0xc45/0x10d0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc34ea53242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffc758046c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fc34e7ad000 RCX: 00007fc34ea53242
RDX: 0000000000000005 RSI: 000000000014e000 RDI: 00007fc34e7ad000
RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000028000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc75804718
R13: 00007fc34ea275f0 R14: 00007ffc75804f00 R15: 00000fff8eb008dc
 </TASK>
rcu: rcu_preempt kthread starved for 10210 jiffies! g10297 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:26696 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5360 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
 __schedule_loop kernel/sched/core.c:7046 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7061
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5873 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e6 7f 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 91 7b 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 75 7b
RSP: 0000:ffffc900039f7700 EFLAGS: 00000293
RAX: ffffffff81b457ab RBX: 1ffff110170e8005 RCX: ffff88801ffb1e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900039f7880 R08: ffffffff8fc43c37 R09: 1ffffffff1f88786
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: ffff8880b8740028
R13: dffffc0000000000 R14: ffff8880b863b240 R15: 0000000000000001
FS:  00007f45a83bc880(0000) GS:ffff8881259e0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005593b3898568 CR3: 000000007210a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
 wp_page_copy mm/memory.c:3780 [inline]
 do_wp_page+0x1bc2/0x5800 mm/memory.c:4175
 handle_pte_fault mm/memory.c:6233 [inline]
 __handle_mm_fault+0x102e/0x5440 mm/memory.c:6360
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6529
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f45a7cb5b69
Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffca257670 EFLAGS: 00010202
RAX: 00007f45a7df21d0 RBX: 00005593b3898540 RCX: 00005593b3898540
RDX: 00005593b3898540 RSI: 00007f45a7df21d0 RDI: 00005593b3898540
RBP: 00007f45a7df1ac0 R08: 0000000000002760 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000049c0
R13: 00005593b389cf00 R14: 0000000000002020 R15: 00007f45a7df1ac0
 </TASK>