syzbot


BUG: sleeping function called from invalid context in kcov_remote_start

Status: upstream: reported on 2025/08/03 15:34
Subsystems: usb
[Documentation on labels]
Reported-by: syzbot+13149748d17d82b13f66@syzkaller.appspotmail.com
First crash: 49d, last: 49d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] BUG: sleeping function called from invalid context in kcov_remote_start 0 (1) 2025/08/03 15:34

Sample crash report:
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: ffffffff8d64a580 (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: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #6: ffff8880b8928b78 ((lock)#3){....}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b78 ((lock)#3){....}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 3767
hardirqs last  enabled at (3766): [<ffffffff8af19435>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (3766): [<ffffffff8af19435>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (3767): [<ffffffff86a3fdb5>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (3767): [<ffffffff86a3fdb5>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (3752): [<ffffffff81850eae>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (3752): [<ffffffff81850eae>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (3758): [<ffffffff818e8d62>] smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Not tainted 6.16.0-syzkaller-04405-g4b290aae788e #0 PREEMPT_{RT,(full)} 
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:8950
 __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:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3581
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: ffffffff8d64a580 (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: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 10365
hardirqs last  enabled at (10364): [<ffffffff8af19435>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (10364): [<ffffffff8af19435>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (10365): [<ffffffff86a3fdb5>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (10365): [<ffffffff86a3fdb5>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (10350): [<ffffffff81850eae>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (10350): [<ffffffff81850eae>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (10356): [<ffffffff818e8d62>] smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-04405-g4b290aae788e #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:8950
 __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:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3581
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: ffffffff8d64a580 (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: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 15439
hardirqs last  enabled at (15438): [<ffffffff8af19435>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (15438): [<ffffffff8af19435>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (15439): [<ffffffff86a3fdb5>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (15439): [<ffffffff86a3fdb5>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (15424): [<ffffffff81850eae>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (15424): [<ffffffff81850eae>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (15430): [<ffffffff818e8d62>] smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-04405-g4b290aae788e #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:8950
 __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:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3581
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: ffffffff8d64a580 (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: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 25001
hardirqs last  enabled at (25000): [<ffffffff8af19435>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (25000): [<ffffffff8af19435>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (25001): [<ffffffff86a3fdb5>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (25001): [<ffffffff86a3fdb5>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (24986): [<ffffffff81850eae>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (24986): [<ffffffff81850eae>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (24992): [<ffffffff818e8d62>] smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-04405-g4b290aae788e #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:8950
 __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:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3581
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: ffffffff8d64a580 (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: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #2: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1bb/0x2c0 kernel/locking/spinlock_rt.c:57
 #3: ffffffff8d7aa040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #4: ffff888019899d38 ((wq_completion)events_bh){+...}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #5: ffffc90000a4fa00 ((work_completion)(&bh->bh)){+...}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #6: ffff8880b8928b78 ((lock)#3){+.+.}-{3:3}, at: kcov_remote_start+0x92/0x460 kernel/kcov.c:865
irq event stamp: 34711
hardirqs last  enabled at (34710): [<ffffffff8af19435>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (34710): [<ffffffff8af19435>] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
hardirqs last disabled at (34711): [<ffffffff86a3fdb5>] kcov_remote_start_usb_softirq include/linux/kcov.h:88 [inline]
hardirqs last disabled at (34711): [<ffffffff86a3fdb5>] __usb_hcd_giveback_urb+0x3f5/0x710 drivers/usb/core/hcd.c:1662
softirqs last  enabled at (34696): [<ffffffff81850eae>] ksoftirqd_run_end kernel/softirq.c:282 [inline]
softirqs last  enabled at (34696): [<ffffffff81850eae>] run_ksoftirqd+0xce/0x210 kernel/softirq.c:969
softirqs last disabled at (34702): [<ffffffff818e8d62>] smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-04405-g4b290aae788e #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:8950
 __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:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 bh_worker+0x2b1/0x600 kernel/workqueue.c:3581
 tasklet_action+0xc/0x70 kernel/softirq.c:854
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/30 15:24 upstream 4b290aae788e f8f2b4da .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: sleeping function called from invalid context in kcov_remote_start
* Struck through repros no longer work on HEAD.