[v5.15] BUG: soft lockup in sys_mmap

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10272ef0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=a308841293a528019889
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a30884...@syzkaller.appspotmail.com

sched: RT throttling activated
vkms_vblank_simulate: vblank timer overrun
watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [syz.1.256:4932]
Modules linked in:
irq event stamp: 47264
hardirqs last enabled at (47263): [<ffff80000874a22c>] count_memcg_events include/linux/memcontrol.h:1058 [inline]
hardirqs last enabled at (47263): [<ffff80000874a22c>] count_memcg_event_mm+0x1b0/0x308 include/linux/memcontrol.h:1081
hardirqs last disabled at (47264): [<ffff8000111baf54>] enter_el1_irq_or_nmi+0x10/0x1c arch/arm64/kernel/entry-common.c:227
softirqs last enabled at (19898): [<ffff80000819e9e8>] softirq_handle_end kernel/softirq.c:419 [inline]
softirqs last enabled at (19898): [<ffff80000819e9e8>] handle_softirqs+0xa4c/0xbf0 kernel/softirq.c:604
softirqs last disabled at (19891): [<ffff80000819efec>] __do_softirq kernel/softirq.c:610 [inline]
softirqs last disabled at (19891): [<ffff80000819efec>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (19891): [<ffff80000819efec>] invoke_softirq kernel/softirq.c:457 [inline]
softirqs last disabled at (19891): [<ffff80000819efec>] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659
CPU: 1 PID: 4932 Comm: syz.1.256 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : lockdep_enabled kernel/locking/lockdep.c:88 [inline]
pc : lock_is_held_type+0x48/0x198 kernel/locking/lockdep.c:5659
lr : lockdep_enabled kernel/locking/lockdep.c:88 [inline]
lr : lock_is_held_type+0x48/0x198 kernel/locking/lockdep.c:5659
sp : ffff800020077440
x29: ffff800020077440 x28: ffff800020077618 x27: ffff8000143c36e0
x26: fffffc0003b3a6c8 x25: ffff8000140c3d40 x24: 1ffff0000400eec0
x23: dfff800000000000 x22: ffff0000def7bca8 x21: ffff0000e8937998
x20: 00000000ffffffff x19: fffffc0003b3a6c0 x18: 0000000000000001
x17: 0000000000000002 x16: ffff8000082c0b70 x15: 0000000000000406
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000ff0100
x11: 0000000000000001 x10: 0000000000000003 x9 : 0000000000000003
x8 : 0000000000000000 x7 : ffff8000086712b0 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800008675730
x2 : 0000000000000004 x1 : 00000000ffffffff x0 : 0000000000000000
Call trace:
lockdep_enabled kernel/locking/lockdep.c:88 [inline]
lock_is_held_type+0x48/0x198 kernel/locking/lockdep.c:5659
lock_is_held include/linux/lockdep.h:287 [inline]
xa_entry include/linux/xarray.h:1182 [inline]
xas_reload+0xf4/0x448 include/linux/xarray.h:1558
next_uptodate_page+0x254/0x734 mm/filemap.c:3259
next_map_page mm/filemap.c:3296 [inline]
filemap_map_pages+0x968/0xc50 mm/filemap.c:3352
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+0x19c0/0x2950 mm/memory.c:4883
faultin_page mm/gup.c:976 [inline]
__get_user_pages+0x3f4/0x9a4 mm/gup.c:1197
populate_vma_page_range+0x1f4/0x284 mm/gup.c:1529
__mm_populate+0x238/0x36c mm/gup.c:1638
mm_populate include/linux/mm.h:2635 [inline]
vm_mmap_pgoff+0x1cc/0x284 mm/util.c:556
ksys_mmap_pgoff+0x11c/0x620 mm/mmap.c:1631
__do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
__se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
__arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.