Forwarded: Re: [syzbot] [fuse?] BUG: scheduling while atomic in __synchronize_srcu

[syzbot]

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Subject: Re: [syzbot] [fuse?] BUG: scheduling while atomic in __synchronize_srcu
Author: maz@xxxxxxxxxx

On Thu, 09 Apr 2026 19:30:19 +0100,
syzbot <syzbot+12b178b7c756664d2518@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> 
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    7f87a5ea75f0 Merge tag 'hid-for-linus-2026040801' of git:/..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=12439316580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2d08886358f27e8c
> dashboard link: https://syzkaller.appspot.com/bug?extid=12b178b7c756664d2518
> compiler:       aarch64-linux-gnu-gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> userspace arch: arm64
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1461aeba580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14c85e06580000
> 
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/fa3fbcfdac58/non_bootable_disk-7f87a5ea.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/28f02ff1720d/vmlinux-7f87a5ea.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/7d30b9e8505e/Image-7f87a5ea.gz.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+12b178b7c756664d2518@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> BUG: scheduling while atomic: syz.1.49/3699/0x00000002
> Modules linked in:
> CPU: 1 UID: 0 PID: 3699 Comm: syz.1.49 Not tainted syzkaller #0 PREEMPT 
> Hardware name: linux,dummy-virt (DT)
> Call trace:
>  dump_backtrace arch/arm64/kernel/stacktrace.c:498 [inline] (C)
>  show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x60/0x80 lib/dump_stack.c:120
>  dump_stack+0x18/0x24 lib/dump_stack.c:129
>  __schedule_bug+0x54/0x78 kernel/sched/core.c:5847
>  schedule_debug kernel/sched/core.c:5874 [inline]
>  __schedule+0x858/0xd84 kernel/sched/core.c:6786
>  __schedule_loop kernel/sched/core.c:6993 [inline]
>  schedule+0x34/0x114 kernel/sched/core.c:7008
>  schedule_timeout+0xd4/0x110 kernel/time/sleep_timeout.c:75
>  do_wait_for_common kernel/sched/completion.c:100 [inline]
>  __wait_for_common kernel/sched/completion.c:121 [inline]
>  wait_for_common kernel/sched/completion.c:132 [inline]
>  wait_for_completion+0x78/0x160 kernel/sched/completion.c:153
>  __synchronize_srcu+0x90/0xd0 kernel/rcu/srcutree.c:1496
>  synchronize_srcu_expedited+0x24/0x40 kernel/rcu/srcutree.c:1521
>  kvm_set_irq_routing+0x204/0x294 virt/kvm/irqchip.c:225
>  kvm_vgic_setup_default_irq_routing+0x78/0xc0 arch/arm64/kvm/vgic/vgic-irqfd.c:153
>  vgic_init+0x1ac/0x268 arch/arm64/kvm/vgic/vgic-init.c:421
>  vgic_lazy_init+0x54/0x6c arch/arm64/kvm/vgic/vgic-init.c:550
>  kvm_vgic_inject_irq+0x30/0x12c arch/arm64/kvm/vgic/vgic.c:520
>  kvm_timer_update_irq+0x68/0x7c arch/arm64/kvm/arch_timer.c:450
>  kvm_timer_vcpu_reset+0xd8/0x1e0 arch/arm64/kvm/arch_timer.c:1036
>  kvm_reset_vcpu+0x194/0x360 arch/arm64/kvm/reset.c:268
>  kvm_vcpu_set_target arch/arm64/kvm/arm.c:1632 [inline]
>  kvm_arch_vcpu_ioctl_vcpu_init arch/arm64/kvm/arm.c:1652 [inline]
>  kvm_arch_vcpu_ioctl+0x2e4/0x8c8 arch/arm64/kvm/arm.c:1773
>  kvm_vcpu_ioctl+0x4ac/0x8f4 virt/kvm/kvm_main.c:4653
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:597 [inline]
>  __se_sys_ioctl fs/ioctl.c:583 [inline]
>  __arm64_sys_ioctl+0xac/0x104 fs/ioctl.c:583
>  __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
>  invoke_syscall+0x48/0x104 arch/arm64/kernel/syscall.c:49
>  el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
>  do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
>  el0_svc+0x34/0x124 arch/arm64/kernel/entry-common.c:724
>  el0t_64_sync_handler+0xa0/0xf0 arch/arm64/kernel/entry-common.c:743
>  el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:596
> BUG: scheduling while atomic: syz.1.49/3699/0x00000000
> Modules linked in:
> CPU: 1 UID: 0 PID: 3699 Comm: syz.1.49 Tainted: G        W           syzkaller #0 PREEMPT 
> Tainted: [W]=WARN
> Hardware name: linux,dummy-virt (DT)
> Call trace:
>  dump_backtrace arch/arm64/kernel/stacktrace.c:498 [inline] (C)
>  show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x60/0x80 lib/dump_stack.c:120
>  dump_stack+0x18/0x24 lib/dump_stack.c:129
>  __schedule_bug+0x54/0x78 kernel/sched/core.c:5847
>  schedule_debug kernel/sched/core.c:5874 [inline]
>  __schedule+0x858/0xd84 kernel/sched/core.c:6786
>  __schedule_loop kernel/sched/core.c:6993 [inline]
>  schedule+0x34/0x114 kernel/sched/core.c:7008
>  futex_do_wait kernel/futex/waitwake.c:358 [inline]
>  __futex_wait+0xf0/0x178 kernel/futex/waitwake.c:687
>  futex_wait+0x88/0x118 kernel/futex/waitwake.c:715
>  do_futex+0xf8/0x1a0 kernel/futex/syscalls.c:130
>  __do_sys_futex kernel/futex/syscalls.c:207 [inline]
>  __se_sys_futex kernel/futex/syscalls.c:188 [inline]
>  __arm64_sys_futex+0xfc/0x1a0 kernel/futex/syscalls.c:188
>  __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
>  invoke_syscall+0x48/0x104 arch/arm64/kernel/syscall.c:49
>  el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
>  do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
>  el0_svc+0x34/0x124 arch/arm64/kernel/entry-common.c:724
>  el0t_64_sync_handler+0xa0/0xf0 arch/arm64/kernel/entry-common.c:743
>  el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:596
> psi: inconsistent task state! task=30:pr/ttyAMA-1 cpu=1 psi_flags=14 clear=0 set=10

#syz set subsystems: kvmarm

#syz test