linux-kernel - [syzbot] [kernel?] KMSAN: uninit-value in psi_group

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Message-ID: <692447eb.a70a0220.d98e3.0087.GAE@google.com>
Date: Mon, 24 Nov 2025 03:56:27 -0800
From: syzbot <syzbot+864964d448db80eb0593@...kaller.appspotmail.com>
To: bp@...en8.de, dave.hansen@...ux.intel.com, hpa@...or.com, 
	linux-kernel@...r.kernel.org, mingo@...hat.com, 
	syzkaller-bugs@...glegroups.com, tglx@...utronix.de, x86@...nel.org
Subject: [syzbot] [kernel?] KMSAN: uninit-value in psi_group_change

Hello,

syzbot found the following issue on:

HEAD commit:    23cb64fb7625 Merge tag 'soc-fixes-6.18-3' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1354f692580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=61a9bf3cc5d17a01
dashboard link: https://syzkaller.appspot.com/bug?extid=864964d448db80eb0593
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/af4aff9f19b2/disk-23cb64fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c70c6cd0be2c/vmlinux-23cb64fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d1634eb1df91/bzImage-23cb64fb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+864964d448db80eb0593@...kaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in psi_group_change+0xf98/0x13c0 kernel/sched/psi.c:845
 psi_group_change+0xf98/0x13c0 kernel/sched/psi.c:845
 psi_task_change+0x390/0x710 kernel/sched/psi.c:922
 psi_dequeue kernel/sched/stats.h:191 [inline]
 dequeue_task+0x6c5/0x770 kernel/sched/core.c:2117
 deactivate_task+0x51/0x70 kernel/sched/core.c:2152
 detach_task+0x119/0x360 kernel/sched/fair.c:9496
 detach_tasks kernel/sched/fair.c:9632 [inline]
 sched_balance_rq+0x7cc8/0xa700 kernel/sched/fair.c:11807
 sched_balance_newidle+0x668/0x14f0 kernel/sched/fair.c:12855
 pick_next_task_fair+0x95/0xed0 kernel/sched/fair.c:8931
 __pick_next_task+0x120/0x700 kernel/sched/core.c:5969
 pick_next_task kernel/sched/core.c:6054 [inline]
 __schedule+0xc27/0x7790 kernel/sched/core.c:6870
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x17d/0x3c0 kernel/sched/core.c:7026
 worker_thread+0x12f9/0x1590 kernel/workqueue.c:3442
 kthread+0xd5c/0xf00 kernel/kthread.c:463
 ret_from_fork+0x1f5/0x4c0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4985 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 __do_kmalloc_node mm/slub.c:5649 [inline]
 __kmalloc_node_track_caller_noprof+0xb4b/0x1ba0 mm/slub.c:5759
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x8a/0x2a0 mm/util.c:84
 kstrdup_const+0x5e/0x90 mm/util.c:104
 kvasprintf_const+0x195/0x370 lib/kasprintf.c:-1
 kobject_set_name_vargs+0x87/0x2f0 lib/kobject.c:274
 kobject_add_varg lib/kobject.c:368 [inline]
 kobject_init_and_add+0x2f4/0x4e0 lib/kobject.c:457
 bus_add_driver+0x41e/0xdb0 drivers/base/bus.c:671
 driver_register+0x42e/0x6a0 drivers/base/driver.c:249
 __auxiliary_driver_register+0x24f/0x380 drivers/base/auxiliary.c:376
 ljca_spi_driver_init+0x2c/0x40 drivers/spi/spi-ljca.c:290
 do_one_initcall+0x237/0xb60 init/main.c:1283
 do_initcall_level+0x157/0x2e0 init/main.c:1345
 do_initcalls+0x176/0x310 init/main.c:1361
 do_basic_setup+0x1d/0x30 init/main.c:1380
 kernel_init_freeable+0x275/0x4a0 init/main.c:1593
 kernel_init+0x2f/0x5e0 init/main.c:1483
 ret_from_fork+0x1f5/0x4c0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

CPU: 1 UID: 0 PID: 3781 Comm: kworker/u8:13 Tainted: G        W           syzkaller #0 PREEMPT(none) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue:  0x0 (events_unbound)
=====================================================


---
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