Re: [syzbot] [kernel?] WARNING in enqueue_dl_entity

From: syzbot
Date: Fri Nov 22 2024 - 17:51:09 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: 28eb75e178d3 Merge tag 'drm-next-2024-11-21' of https://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1402175f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5606b6814de0f638
dashboard link: https://syzkaller.appspot.com/bug?extid=00a022dc9979d67df050
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=1016fec0580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-28eb75e1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4053ed867efd/vmlinux-28eb75e1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/903039310aac/Image-28eb75e1.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+00a022dc9979d67df050@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 0 PID: 10 at kernel/sched/deadline.c:1995 enqueue_dl_entity+0x478/0x58c kernel/sched/deadline.c:2029
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.12.0-syzkaller-07749-g28eb75e178d3 #0
Hardware name: linux,dummy-virt (DT)
Workqueue: 0x0 (events)
pstate: a14000c9 (NzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : enqueue_dl_entity+0x478/0x58c kernel/sched/deadline.c:1995
lr : dl_server_start+0x44/0x12c kernel/sched/deadline.c:1650
sp : ffff800082b33a10
x29: ffff800082b33a10 x28: fdf0000004e5dc00 x27: 0000000000000000
x26: 0000000000000001 x25: 0000000000000000 x24: 0000000000000048
x23: fff000007f8d7600 x22: 0000000000000001 x21: 000000000016e360
x20: 0000000000000001 x19: fff000007f8d7f68 x18: 0000000000000000
x17: 0000000000000004 x16: 0000000000000002 x15: 0000000000000000
x14: 0000000000000142 x13: 00000000000003db x12: 0000000000000001
x11: fff000007f8d7680 x10: 0000000000000284 x9 : 0000000000000048
x8 : 0000000000100000 x7 : 0000000000000000 x6 : fdf0000004e5dbc0
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000001
Call trace:
enqueue_dl_entity+0x478/0x58c kernel/sched/deadline.c:2029 (P)
dl_server_start+0x44/0x12c kernel/sched/deadline.c:1650 (L)
dl_server_start+0x44/0x12c kernel/sched/deadline.c:1650
enqueue_task_fair+0x11c/0x3a4 kernel/sched/fair.c:7038
enqueue_task+0x3c/0xe4 kernel/sched/core.c:2061
activate_task+0x68/0x80 kernel/sched/core.c:2108
attach_task+0x4c/0x74 kernel/sched/fair.c:9635
attach_tasks kernel/sched/fair.c:9670 [inline]
sched_balance_rq+0x580/0xc74 kernel/sched/fair.c:11747
sched_balance_newidle.constprop.0+0x1b0/0x3e4 kernel/sched/fair.c:12789
pick_next_task_fair+0x50/0x320 kernel/sched/fair.c:8937
__pick_next_task kernel/sched/core.c:6023 [inline]
pick_next_task kernel/sched/core.c:6542 [inline]
__schedule+0x15c/0x900 kernel/sched/core.c:6709
__schedule_loop kernel/sched/core.c:6833 [inline]
schedule+0x34/0x104 kernel/sched/core.c:6848
worker_thread+0x19c/0x354 kernel/workqueue.c:3406
kthread+0x114/0x118 kernel/kthread.c:389
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862
---[ end trace 0000000000000000 ]---


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