syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3751/1:b..l P3756/1:b..l
	(detected by 1, t=10503 jiffies, g=7441, q=1046 ncpus=2)
task:sed             state:R  running task     stack:22616 pid:3756  ppid:3753   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xffa/0x12c0 mm/filemap.c:3470
 do_fault_around mm/memory.c:4581 [inline]
 do_read_fault mm/memory.c:4607 [inline]
 do_fault mm/memory.c:4741 [inline]
 handle_pte_fault mm/memory.c:5013 [inline]
 __handle_mm_fault mm/memory.c:5155 [inline]
 handle_mm_fault+0x33e2/0x5340 mm/memory.c:5276
 do_user_addr_fault arch/x86/mm/fault.c:1371 [inline]
 handle_page_fault arch/x86/mm/fault.c:1462 [inline]
 exc_page_fault+0x26f/0x660 arch/x86/mm/fault.c:1518
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f87002d04d3
RSP: 002b:00007ffc22d82508 EFLAGS: 00010202
RAX: 0000000000000015 RBX: 00007f87003ec400 RCX: 0000000000000000
RDX: 000000000000000d RSI: 00007f87003e6261 RDI: 00007f870024c3c0
RBP: 00007ffc22d82610 R08: 00007ffc22d82488 R09: 00007f87004a25c0
R10: 00007f87003e1778 R11: 0000000000000007 R12: 00007f87004a20c0
R13: 00007f87002d04d3 R14: 00007f87004a06b0 R15: 00007f87004a3c30
 </TASK>
task:syz-executor.1  state:R  running task     stack:25048 pid:3751  ppid:3559   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:206
Code: 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 48 ea e8 0c 48 89 de 5b e9 57 a0 56 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0d d4 df 77 7e 65 8b 15 d5 df 77 7e f7 c2 00 01 ff 00 74
RSP: 0018:ffffc900059370f0 EFLAGS: 00000202
RAX: ffffffff81eca094 RBX: 0000000000000001 RCX: ffff88801975d940
RDX: ffff88801975d940 RSI: ffffffff8b3d4300 RDI: ffffffff8b3d42c0
RBP: 0000000000000001 R08: ffffffff81eca082 R09: ffffed1002bb5455
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000000000 R14: ffffea000157ad00 R15: 0000000000140cca
 rcu_read_unlock include/linux/rcupdate.h:820 [inline]
 page_ext_put+0x34/0xb0 mm/page_ext.c:182
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513
 prep_new_page mm/page_alloc.c:2520 [inline]
 get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547
 __folio_alloc+0xf/0x30 mm/page_alloc.c:5579
 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243
 shmem_alloc_folio mm/shmem.c:1589 [inline]
 shmem_alloc_and_acct_folio+0x5a8/0xd50 mm/shmem.c:1613
 shmem_get_folio_gfp+0x13f0/0x3470 mm/shmem.c:1941
 shmem_get_folio mm/shmem.c:2072 [inline]
 shmem_write_begin+0x16e/0x4e0 mm/shmem.c:2559
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3817
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3945
 generic_file_write_iter+0xab/0x310 mm/filemap.c:3977
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x7ae/0xba0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f014ba7cbef
RSP: 002b:00007f014c891e80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f014ba7cbef
RDX: 0000000001000000 RSI: 00007f01421f7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009600
R10: 0000000020012cc2 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f014c891f80 R14: 00007f014c891f40 R15: 00007f01421f7000
 </TASK>
rcu: rcu_preempt kthread starved for 10570 jiffies! g7441 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27032 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 3764 Comm: syz-executor.0 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0033:0x7fd616ea5630
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 3a 9a 04 00 e8 35 78 fa ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007ffdfb05c3f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000032 RCX: 00007fd616e7dea9
RDX: 00007ffdfb05c400 RSI: 00007ffdfb05c530 RDI: 0000000000000021
RBP: 00007fd616fac05c R08: 0000000000000010 R09: 00007ffdfb05c9d0
R10: 00007ffdfb05cb30 R11: 0000000000000246 R12: 0000000000025e9a
R13: 0000000000025e68 R14: 00007ffdfb05cb50 R15: 00007fd616e34cb0
FS:  0000555556c15480 GS:  0000000000000000
sched: RT throttling activated