Message-ID: <688cf3e0.a00a0220.26d0e1.0074.GAE@google.com>
Date: Fri, 01 Aug 2025 10:05:36 -0700
From: syzbot <syzbot+95069c82577357ff89d8@...kaller.appspotmail.com>
To: gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org, 
	linux-usb@...r.kernel.org, llvm@...ts.linux.dev, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [usb?] upstream test error: BUG: sleeping function called
 from invalid context in kcov_remote_start

Hello,

syzbot found the following issue on:

HEAD commit:    89748acdf226 Merge tag 'drm-next-2025-08-01' of https://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164a9cf0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=caba3b7d5edc3bd1
dashboard link: https://syzkaller.appspot.com/bug?extid=95069c82577357ff89d8
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7d6418d10fb8/disk-89748acd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4608f748b818/vmlinux-89748acd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92e2adcd74de/bzImage-89748acd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+95069c82577357ff89d8@...kaller.appspotmail.com

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 30, name: ksoftirqd/1
preempt_count: 0, expected: 0
RCU nest depth: 2, expected: 2
7 locks held by ksoftirqd/1/30:
 #0: ffffffff8d64a6a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #1: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #1: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: __local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
 #2: ffffffff8d7a8b00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7a8b00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7a8b00 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7a8b00 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7a8b00 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff88801989a138 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #4: ffff88801989a138 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #6: ffff8880b8928b50 ((lock)#3){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b50 ((lock)#3){+.+.}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 58091
hardirqs last  enabled at (58090): [<ffffffff8af459c5>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (58090): [<ffffffff8af459c5>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (58091): [<ffffffff86a72b95>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (58091): [<ffffffff86a72b95>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (58074): [<ffffffff8184ff9e>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (58074): [<ffffffff8184ff9e>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (58082): [<ffffffff818e7aff>] smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-10499-g89748acdf226 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 __might_resched+0x44b/0x5d0 kernel/sched/core.c:8957
 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline]
 rt_spin_lock+0xc7/0x2c0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 kcov_remote_start+0x92/0x460 kernel/kcov.c:865
 kcov_remote_start_usb include/linux/kcov.h:55 [inline]
 kcov_remote_start_usb_softirq include/linux/kcov.h:89 [inline]
 __usb_hcd_giveback_urb+0x427/0x710 drivers/usb/core/hcd.c:1662
 usb_giveback_urb_bh+0x296/0x420 drivers/usb/core/hcd.c:1697
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3579
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22f/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@...glegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Powered by blists - more mailing lists