[syzbot] [mm?] kernel panic: corrupted stack end in userfaultfd_ioctl

[syzbot <syzbot+5a1cb2c00e895afca87e@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    4a4be1ad3a6e Revert "vfs: Delete the associated dentry whe..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=104284f2980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bd6024aedb15e15c
dashboard link: https://syzkaller.appspot.com/bug?extid=5a1cb2c00e895afca87e
compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=124e1664980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15683162980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-4a4be1ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/75957361122b/vmlinux-4a4be1ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6c766b0ec377/Image-4a4be1ad.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5a1cb2c00e895afca87e@syzkaller.appspotmail.com

Kernel panic - not syncing: corrupted stack end detected inside scheduler
CPU: 1 PID: 3188 Comm: syz-executor396 Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x94/0xec arch/arm64/kernel/stacktrace.c:317
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:324
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x38/0x90 lib/dump_stack.c:114
 dump_stack+0x18/0x24 lib/dump_stack.c:123
 panic+0x39c/0x3d0 kernel/panic.c:347
 schedule_debug kernel/sched/core.c:5962 [inline]
 schedule+0x0/0x104 kernel/sched/core.c:6628
 preempt_schedule_irq+0x3c/0x80 kernel/sched/core.c:7067
 arm64_preempt_schedule_irq arch/arm64/kernel/entry-common.c:301 [inline]
 __el1_irq arch/arm64/kernel/entry-common.c:539 [inline]
 el1_interrupt+0x4c/0x64 arch/arm64/kernel/entry-common.c:551
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:556
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:594
 __rcu_read_lock+0x0/0x14 kernel/rcu/tree_stall.h:125
 pte_offset_map_nolock+0x38/0xb0 mm/pgtable-generic.c:314
 move_pages_pte mm/userfaultfd.c:1160 [inline]
 move_pages+0x330/0x13a4 mm/userfaultfd.c:1733
 userfaultfd_move fs/userfaultfd.c:2016 [inline]
 userfaultfd_ioctl+0x6f4/0x1ed8 fs/userfaultfd.c:2134
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl fs/ioctl.c:893 [inline]
 __arm64_sys_ioctl+0xac/0xf0 fs/ioctl.c:893
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x48/0x118 arch/arm64/kernel/syscall.c:48
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:152
 el0_svc+0x34/0xf8 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598
SMP: stopping secondary CPUs
Kernel Offset: disabled
CPU features: 0x00,00000006,8f17bd7c,1767f6bf
Memory Limit: none
Rebooting in 86400 seconds..


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