[v5.15] INFO: rcu detected stall in mmap_pgoff (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 43bb85222e53 Linux 5.15.193
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=128e38e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=7ed811a7f17b58c8cdcd
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/aa8fda38f146/disk-43bb8522.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5cfcd43783fc/vmlinux-43bb8522.xz
kernel image: https://storage.googleapis.com/syzbot-assets/582ede77e278/bzImage-43bb8522.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7ed811...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5077/1:b..l P5068/1:b..l
(detected by 1, t=10502 jiffies, g=12369, q=15)
task:sed state:R running task stack:26312 pid: 5068 ppid: 5066 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6596
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:403 [inline]
filemap_map_pages+0x1031/0x1390 mm/filemap.c:3353
do_fault_around mm/memory.c:4243 [inline]
do_read_fault mm/memory.c:4258 [inline]
do_fault mm/memory.c:4392 [inline]
handle_pte_fault mm/memory.c:4650 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x2580/0x43c0 mm/memory.c:4883
do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
handle_page_fault arch/x86/mm/fault.c:1445 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f0a831d22d0
RSP: 002b:00007ffd70b52488 EFLAGS: 00010202
RAX: 0000000000000275 RBX: 0000000000000001 RCX: 00007f0a83467300
RDX: 00007f0a8321ccd0 RSI: 00000000000013a8 RDI: 0000000000000001
RBP: 00007ffd70b52760 R08: 00007f0a834686a8 R09: 0000000000000000
R10: 00007ffd70b52490 R11: 0000000000000246 R12: fffffffffffffff8
R13: 00000049115f604f R14: 0000000000000000 R15: 00007f0a8346a310
</TASK>
task:syz.5.160 state:R running task stack:25376 pid: 5077 ppid: 4528 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline]
RIP: 0010:lock_is_held_type+0x68/0x190 kernel/locking/lockdep.c:5662
Code: 48 8b 1d bb 7e 59 76 83 bb ec 0a 00 00 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 4c 8b 2c 24 <fa> 48 c7 c7 20 26 0b 8a e8 4b 0e 00 00 65 ff 05 04 88 59 76 83 bb
RSP: 0018:ffffc9000336f678 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802b2c9dc0 RCX: 5b5dd42c9299f400
RDX: 0000000000000002 RSI: 00000000ffffffff RDI: ffffffff8c11c660
RBP: 00000000ffffffff R08: dffffc0000000000 R09: fffff940002d3d7f
R10: fffff940002d3d7f R11: 1ffffd40002d3d7e R12: ffff88807afb2288
R13: 0000000000000246 R14: ffffffff8c11c660 R15: 00000000ffffffff
xa_entry include/linux/xarray.h:1197 [inline]
xas_reload+0x19c/0x470 include/linux/xarray.h:1573
next_uptodate_page+0x2a5/0x8b0 mm/filemap.c:3259
first_map_page mm/filemap.c:3288 [inline]
filemap_map_pages+0x216/0x1390 mm/filemap.c:3314
do_fault_around mm/memory.c:4243 [inline]
do_read_fault mm/memory.c:4258 [inline]
do_fault mm/memory.c:4392 [inline]
handle_pte_fault mm/memory.c:4650 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x2580/0x43c0 mm/memory.c:4883
faultin_page mm/gup.c:976 [inline]
__get_user_pages+0x93e/0x11c0 mm/gup.c:1197
populate_vma_page_range+0x213/0x290 mm/gup.c:1529
__mm_populate+0x26f/0x3a0 mm/gup.c:1638
mm_populate include/linux/mm.h:2646 [inline]
vm_mmap_pgoff+0x203/0x2b0 mm/util.c:556
ksys_mmap_pgoff+0x140/0x780 mm/mmap.c:1635
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa8a05aeec9
RSP: 002b:00007fa89e816038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fa8a0805fa0 RCX: 00007fa8a05aeec9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fa8a0631f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa8a0806038 R14: 00007fa8a0805fa0 R15: 00007ffc99d768a8
</TASK>
rcu: rcu_preempt kthread starved for 10552 jiffies! g12369 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:27368 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729


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