* [syzbot] [mmc?] WARNING: suspicious RCU usage in cancel_delayed_work_sync
@ 2026-08-14 15:11 syzbot
0 siblings, 0 replies; only message in thread
From: syzbot @ 2026-08-14 15:11 UTC (permalink / raw)
To: linux-kernel, linux-mmc, linux-usb, syzkaller-bugs, ulf.hansson,
ulfh
Hello,
syzbot found the following issue on:
HEAD commit: 05abeffcc27e Merge tag 'usb-serial-7.3-rc1' of ssh://gitol..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=172cfac6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8bdeea7ee6735f91
dashboard link: https://syzkaller.appspot.com/bug?extid=9c1988bc953fca2086a3
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f63099341558/disk-05abeffc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2f8181068028/vmlinux-05abeffc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7d35739c76eb/bzImage-05abeffc.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c1988bc953fca2086a3@syzkaller.appspotmail.com
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:9159 Illegal context switch in RCU-sched read-side critical section!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
9 locks held by syz-executor/2973:
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x498b/0x7dd0 kernel/fork.c:2289
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x11f/0x1f60 mm/mmap.c:1739
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline]
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1ba/0x1f60 mm/mmap.c:1746
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:404
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1272 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range mm/memory.c:1408 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pud_range mm/memory.c:1445 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_p4d_range mm/memory.c:1469 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_page_range+0xcc2/0x56a0 mm/memory.c:1555
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:938 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xbc/0x4a0 include/linux/mmzone.h:2270
#8: ffffc90000007ca0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11f/0x610 kernel/time/timer.c:1745
stack backtrace:
CPU: 0 UID: 0 PID: 2973 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
lockdep_rcu_suspicious.cold+0x4f/0xb1 kernel/locking/lockdep.c:6876
__might_resched+0x2e0/0x330 kernel/sched/core.c:9159
__cancel_work_sync kernel/workqueue.c:4487 [inline]
cancel_delayed_work_sync+0xb8/0xf0 kernel/workqueue.c:4568
mmc_free_host+0x19/0x30 drivers/mmc/core/host.c:700
vub300_delete drivers/mmc/host/vub300.c:379 [inline]
kref_put include/linux/kref.h:65 [inline]
vub300_inactivity_timer_expired drivers/mmc/host/vub300.c:747 [inline]
vub300_inactivity_timer_expired+0x42f/0x550 drivers/mmc/host/vub300.c:742
call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x160/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:check_preemption_disabled+0x26/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 65 1f 82 05 65 f7 05 56 1f 82 05 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c <c3> cc cc cc cc 9c 58 f6 c4 02 74 ea 65 4c 8b 25 1e 1f 82 05 48 89
RSP: 0018:ffffc90001457430 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000125cae RCX: ffffffff82216929
RDX: ffff8881236b0000 RSI: ffffffff87b15680 RDI: ffffffff87b156c0
RBP: ffff88823ff5d480 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88823ff5e000 R14: dffffc0000000000 R15: 0000000000000000
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
rcu_read_lock_sched include/linux/rcupdate.h:939 [inline]
pfn_valid+0x2d0/0x4a0 include/linux/mmzone.h:2270
page_table_check_set+0x25/0x580 mm/page_table_check.c:105
__page_table_check_ptes_set+0x217/0x270 mm/page_table_check.c:223
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c87/0x56a0 mm/memory.c:1555
dup_mmap+0xcd8/0x1f60 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4996/0x7dd0 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fd1056b52
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc26622180 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc26622180 RCX: 00007f2fd1056b52
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffc2662230c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558a3997d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001c243 R15: 00007ffc26622360
</TASK>
BUG: sleeping function called from invalid context at kernel/workqueue.c:4487
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2973, name: syz-executor
preempt_count: 104, expected: 0
RCU nest depth: 2, expected: 0
9 locks held by syz-executor/2973:
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x498b/0x7dd0 kernel/fork.c:2289
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x11f/0x1f60 mm/mmap.c:1739
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline]
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1ba/0x1f60 mm/mmap.c:1746
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:404
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1272 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range mm/memory.c:1408 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pud_range mm/memory.c:1445 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_p4d_range mm/memory.c:1469 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_page_range+0xcc2/0x56a0 mm/memory.c:1555
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:938 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xbc/0x4a0 include/linux/mmzone.h:2270
#8: ffffc90000007ca0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11f/0x610 kernel/time/timer.c:1745
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 UID: 0 PID: 2973 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
__might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9197
__cancel_work_sync kernel/workqueue.c:4487 [inline]
cancel_delayed_work_sync+0xb8/0xf0 kernel/workqueue.c:4568
mmc_free_host+0x19/0x30 drivers/mmc/core/host.c:700
vub300_delete drivers/mmc/host/vub300.c:379 [inline]
kref_put include/linux/kref.h:65 [inline]
vub300_inactivity_timer_expired drivers/mmc/host/vub300.c:747 [inline]
vub300_inactivity_timer_expired+0x42f/0x550 drivers/mmc/host/vub300.c:742
call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x160/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:check_preemption_disabled+0x26/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 65 1f 82 05 65 f7 05 56 1f 82 05 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c <c3> cc cc cc cc 9c 58 f6 c4 02 74 ea 65 4c 8b 25 1e 1f 82 05 48 89
RSP: 0018:ffffc90001457430 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000125cae RCX: ffffffff82216929
RDX: ffff8881236b0000 RSI: ffffffff87b15680 RDI: ffffffff87b156c0
RBP: ffff88823ff5d480 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88823ff5e000 R14: dffffc0000000000 R15: 0000000000000000
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
rcu_read_lock_sched include/linux/rcupdate.h:939 [inline]
pfn_valid+0x2d0/0x4a0 include/linux/mmzone.h:2270
page_table_check_set+0x25/0x580 mm/page_table_check.c:105
__page_table_check_ptes_set+0x217/0x270 mm/page_table_check.c:223
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c87/0x56a0 mm/memory.c:1555
dup_mmap+0xcd8/0x1f60 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4996/0x7dd0 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fd1056b52
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc26622180 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc26622180 RCX: 00007f2fd1056b52
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffc2662230c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558a3997d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001c243 R15: 00007ffc26622360
</TASK>
=============================
WARNING: suspicious RCU usage
syzkaller #0 Tainted: G W
-----------------------------
kernel/rcu/srcutree.c:1483 Illegal synchronize_srcu() in same-type SRCU (or in RCU) read-side critical section!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
9 locks held by syz-executor/2973:
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x498b/0x7dd0 kernel/fork.c:2289
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x11f/0x1f60 mm/mmap.c:1739
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline]
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1ba/0x1f60 mm/mmap.c:1746
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:404
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1272 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range mm/memory.c:1408 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pud_range mm/memory.c:1445 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_p4d_range mm/memory.c:1469 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_page_range+0xcc2/0x56a0 mm/memory.c:1555
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:938 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xbc/0x4a0 include/linux/mmzone.h:2270
#8: ffffc90000007ca0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11f/0x610 kernel/time/timer.c:1745
stack backtrace:
CPU: 0 UID: 0 PID: 2973 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
lockdep_rcu_suspicious.cold+0x4f/0xb1 kernel/locking/lockdep.c:6876
__synchronize_srcu+0x29d/0x300 kernel/rcu/srcutree.c:1483
wakeup_source_remove drivers/base/power/wakeup.c:201 [inline]
wakeup_source_unregister.part.0+0x12c/0x540 drivers/base/power/wakeup.c:237
wakeup_source_unregister+0x1f/0x30 drivers/base/power/wakeup.c:236
mmc_host_classdev_release+0x42/0x120 drivers/mmc/core/host.c:69
device_release+0xd2/0x270 drivers/base/core.c:2636
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1f7/0x640 lib/kobject.c:737
put_device+0x1f/0x30 drivers/base/core.c:3880
vub300_delete drivers/mmc/host/vub300.c:379 [inline]
kref_put include/linux/kref.h:65 [inline]
vub300_inactivity_timer_expired drivers/mmc/host/vub300.c:747 [inline]
vub300_inactivity_timer_expired+0x42f/0x550 drivers/mmc/host/vub300.c:742
call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x160/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:check_preemption_disabled+0x26/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 65 1f 82 05 65 f7 05 56 1f 82 05 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c <c3> cc cc cc cc 9c 58 f6 c4 02 74 ea 65 4c 8b 25 1e 1f 82 05 48 89
RSP: 0018:ffffc90001457430 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000125cae RCX: ffffffff82216929
RDX: ffff8881236b0000 RSI: ffffffff87b15680 RDI: ffffffff87b156c0
RBP: ffff88823ff5d480 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88823ff5e000 R14: dffffc0000000000 R15: 0000000000000000
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
rcu_read_lock_sched include/linux/rcupdate.h:939 [inline]
pfn_valid+0x2d0/0x4a0 include/linux/mmzone.h:2270
page_table_check_set+0x25/0x580 mm/page_table_check.c:105
__page_table_check_ptes_set+0x217/0x270 mm/page_table_check.c:223
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c87/0x56a0 mm/memory.c:1555
dup_mmap+0xcd8/0x1f60 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4996/0x7dd0 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fd1056b52
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc26622180 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc26622180 RCX: 00007f2fd1056b52
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffc2662230c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558a3997d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001c243 R15: 00007ffc26622360
</TASK>
BUG: sleeping function called from invalid context at kernel/rcu/srcutree.c:1491
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2973, name: syz-executor
preempt_count: 104, expected: 0
RCU nest depth: 2, expected: 0
9 locks held by syz-executor/2973:
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff89823d10 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x498b/0x7dd0 kernel/fork.c:2289
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#1: ffff888123fdceb8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x11f/0x1f60 mm/mmap.c:1739
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline]
#2: ffff888118e9e7b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1ba/0x1f60 mm/mmap.c:1746
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#4: ffff88810cf5e8b8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:404
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff896e2bc0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x300 mm/pgtable-generic.c:290
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1272 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range mm/memory.c:1408 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pud_range mm/memory.c:1445 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_p4d_range mm/memory.c:1469 [inline]
#6: ffff888123d09f18 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_page_range+0xcc2/0x56a0 mm/memory.c:1555
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:938 [inline]
#7: ffffffff896e2b00 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xbc/0x4a0 include/linux/mmzone.h:2270
#8: ffffc90000007ca0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11f/0x610 kernel/time/timer.c:1745
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 UID: 0 PID: 2973 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
__might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9197
__synchronize_srcu+0x13c/0x300 kernel/rcu/srcutree.c:1491
wakeup_source_remove drivers/base/power/wakeup.c:201 [inline]
wakeup_source_unregister.part.0+0x12c/0x540 drivers/base/power/wakeup.c:237
wakeup_source_unregister+0x1f/0x30 drivers/base/power/wakeup.c:236
mmc_host_classdev_release+0x42/0x120 drivers/mmc/core/host.c:69
device_release+0xd2/0x270 drivers/base/core.c:2636
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1f7/0x640 lib/kobject.c:737
put_device+0x1f/0x30 drivers/base/core.c:3880
vub300_delete drivers/mmc/host/vub300.c:379 [inline]
kref_put include/linux/kref.h:65 [inline]
vub300_inactivity_timer_expired drivers/mmc/host/vub300.c:747 [inline]
vub300_inactivity_timer_expired+0x42f/0x550 drivers/mmc/host/vub300.c:742
call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x160/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:check_preemption_disabled+0x26/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 65 1f 82 05 65 f7 05 56 1f 82 05 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c <c3> cc cc cc cc 9c 58 f6 c4 02 74 ea 65 4c 8b 25 1e 1f 82 05 48 89
RSP: 0018:ffffc90001457430 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000125cae RCX: ffffffff82216929
RDX: ffff8881236b0000 RSI: ffffffff87b15680 RDI: ffffffff87b156c0
RBP: ffff88823ff5d480 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff88823ff5e000 R14: dffffc0000000000 R15: 0000000000000000
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
rcu_read_lock_sched include/linux/rcupdate.h:939 [inline]
pfn_valid+0x2d0/0x4a0 include/linux/mmzone.h:2270
page_table_check_set+0x25/0x580 mm/page_table_check.c:105
__page_table_check_ptes_set+0x217/0x270 mm/page_table_check.c:223
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c87/0x56a0 mm/memory.c:1555
dup_mmap+0xcd8/0x1f60 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4996/0x7dd0 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fd1056b52
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc26622180 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc26622180 RCX: 00007f2fd1056b52
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffc2662230c R08: 0000000000000000 R09: 0000000000000001
R10: 000055558a3997d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000001c243 R15: 00007ffc26622360
</TASK>
ODEBUG: object ffffc90000007a70 is NOT on stack ffffc90001450000, but annotated.
======================================================
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 41 54 push %r12
6: 55 push %rbp
7: 53 push %rbx
8: 48 83 ec 08 sub $0x8,%rsp
c: 65 8b 1d 65 1f 82 05 mov %gs:0x5821f65(%rip),%ebx # 0x5821f78
13: 65 f7 05 56 1f 82 05 testl $0x7fffffff,%gs:0x5821f56(%rip) # 0x5821f74
1a: ff ff ff 7f
1e: 74 0f je 0x2f
20: 48 83 c4 08 add $0x8,%rsp
24: 89 d8 mov %ebx,%eax
26: 5b pop %rbx
27: 5d pop %rbp
28: 41 5c pop %r12
* 2a: c3 ret <-- trapping instruction
2b: cc int3
2c: cc int3
2d: cc int3
2e: cc int3
2f: 9c pushf
30: 58 pop %rax
31: f6 c4 02 test $0x2,%ah
34: 74 ea je 0x20
36: 65 4c 8b 25 1e 1f 82 mov %gs:0x5821f1e(%rip),%r12 # 0x5821f5c
3d: 05
3e: 48 rex.W
3f: 89 .byte 0x89
---
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2026-08-14 15:11 [syzbot] [mmc?] WARNING: suspicious RCU usage in cancel_delayed_work_sync syzbot
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