WARNING: suspicious RCU usage in mmc_free_host

Status: upstream: reported on 2026/08/22 06:04
Subsystems: mmc
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+0d22039ef0915696ad4b@syzkaller.appspotmail.com
First crash: 21d, last: 1d04h
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ID Workflow Result Correct Bug Created Started Finished Revision
45d40a75 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING: suspicious RCU usage in mmc_free_host 2026/08/20 00:32 2026/08/20 00:32 2026/08/20 01:21 1e72964b
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mmc?] WARNING: suspicious RCU usage in mmc_free_host 1 (2) 2026/08/24 08:31
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING: suspicious RCU usage in mmc_free_host 4 5 15h34m 13d 0/2 upstream: reported on 2026/08/26 09:11

Sample crash report:
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:9196 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
locks held by syz.1.150/6183: 3, last CPU#1:
 #0: ffff888030d816f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:947 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: fd_install+0x94/0x3d0 fs/file.c:687
 #2: ffffc90000a18cc0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x5f0 kernel/time/timer.c:1745

stack backtrace:
CPU: 1 UID: 0 PID: 6183 Comm: syz.1.150 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 lockdep_rcu_suspicious+0x140/0x1d0 kernel/locking/lockdep.c:6938
 __might_resched+0xbb/0x4c0 kernel/sched/core.c:9196
 __cancel_work_sync+0x6d/0x110 kernel/workqueue.c:4561
 mmc_free_host+0x19/0x30 drivers/mmc/core/host.c:700
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 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:fd_install+0x1df/0x3d0 fs/file.c:696
Code: c1 ef 03 41 80 3c 2f 00 74 08 48 89 df e8 a9 17 e3 ff 45 89 ec 49 c1 e4 03 4c 8b 2b 4d 01 e5 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 87 17 e3 ff 49 83 7d 00 00 0f 85 d2 01 00 00 41
RSP: 0018:ffffc9000bfa76a8 EFLAGS: 00000246
RAX: 1ffff1100a8ea64b RBX: ffff8880276a0108 RCX: 0000000000080000
RDX: ffffc90003ed1000 RSI: 000000000000022a RDI: 000000000000022b
RBP: dffffc0000000000 R08: 0400000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c7a0 R12: 0000000000000258
R13: ffff888054753258 R14: ffffffff825479f4 R15: 1ffff11004ed4021
 scm_recv_one_fd+0x17f/0x210 net/core/scm.c:375
 scm_detach_fds+0x215/0x6b0 net/core/scm.c:397
 scm_recv_unix+0x122/0x420 net/core/scm.c:573
 __unix_dgram_recvmsg+0x9d6/0xd70 net/unix/af_unix.c:2669
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x196/0x1e0 net/socket.c:1173
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2933
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2975
 __sys_recvmsg net/socket.c:3008 [inline]
 __do_sys_recvmsg net/socket.c:3014 [inline]
 __se_sys_recvmsg net/socket.c:3011 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:3011
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99339e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe994198028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fe993625fa0 RCX: 00007fe99339e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fe993435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe993626038 R14: 00007fe993625fa0 R15: 00007fe99374fa48
 </TASK>
BUG: sleeping function called from invalid context at kernel/workqueue.c:4561
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6183, name: syz.1.150
preempt_count: 101, expected: 0
RCU nest depth: 0, expected: 0
locks held by syz.1.150/6183: 3, last CPU#1:
 #0: ffff888030d816f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:947 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: fd_install+0x94/0x3d0 fs/file.c:687
 #2: ffffc90000a18cc0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x5f0 kernel/time/timer.c:1745
Preemption disabled at:
[<ffffffff825479ed>] rcu_read_lock_sched include/linux/rcupdate.h:944 [inline]
[<ffffffff825479ed>] fd_install+0x8d/0x3d0 fs/file.c:687
CPU: 1 UID: 0 PID: 6183 Comm: syz.1.150 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9234
 __cancel_work_sync+0x6d/0x110 kernel/workqueue.c:4561
 mmc_free_host+0x19/0x30 drivers/mmc/core/host.c:700
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 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:fd_install+0x1df/0x3d0 fs/file.c:696
Code: c1 ef 03 41 80 3c 2f 00 74 08 48 89 df e8 a9 17 e3 ff 45 89 ec 49 c1 e4 03 4c 8b 2b 4d 01 e5 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 87 17 e3 ff 49 83 7d 00 00 0f 85 d2 01 00 00 41
RSP: 0018:ffffc9000bfa76a8 EFLAGS: 00000246
RAX: 1ffff1100a8ea64b RBX: ffff8880276a0108 RCX: 0000000000080000
RDX: ffffc90003ed1000 RSI: 000000000000022a RDI: 000000000000022b
RBP: dffffc0000000000 R08: 0400000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c7a0 R12: 0000000000000258
R13: ffff888054753258 R14: ffffffff825479f4 R15: 1ffff11004ed4021
 scm_recv_one_fd+0x17f/0x210 net/core/scm.c:375
 scm_detach_fds+0x215/0x6b0 net/core/scm.c:397
 scm_recv_unix+0x122/0x420 net/core/scm.c:573
 __unix_dgram_recvmsg+0x9d6/0xd70 net/unix/af_unix.c:2669
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x196/0x1e0 net/socket.c:1173
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2933
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2975
 __sys_recvmsg net/socket.c:3008 [inline]
 __do_sys_recvmsg net/socket.c:3014 [inline]
 __se_sys_recvmsg net/socket.c:3011 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:3011
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99339e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe994198028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fe993625fa0 RCX: 00007fe99339e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fe993435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe993626038 R14: 00007fe993625fa0 R15: 00007fe99374fa48
 </TASK>

=============================
WARNING: suspicious RCU usage
syzkaller #0 Tainted: G        W          
-----------------------------
kernel/rcu/srcutree.c:1468 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
locks held by syz.1.150/6183: 3, last CPU#1:
 #0: ffff888030d816f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:947 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: fd_install+0x94/0x3d0 fs/file.c:687
 #2: ffffc90000a18cc0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x5f0 kernel/time/timer.c:1745

stack backtrace:
CPU: 1 UID: 0 PID: 6183 Comm: syz.1.150 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 lockdep_rcu_suspicious+0x140/0x1d0 kernel/locking/lockdep.c:6938
 __synchronize_srcu+0x157/0x2f0 kernel/rcu/srcutree.c:1464
 wakeup_source_remove drivers/base/power/wakeup.c:201 [inline]
 wakeup_source_unregister+0x129/0x3f0 drivers/base/power/wakeup.c:237
 mmc_host_classdev_release+0x47/0x100 drivers/mmc/core/host.c:69
 device_release+0xc4/0x1f0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x222/0x550 lib/kobject.c:737
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 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:fd_install+0x1df/0x3d0 fs/file.c:696
Code: c1 ef 03 41 80 3c 2f 00 74 08 48 89 df e8 a9 17 e3 ff 45 89 ec 49 c1 e4 03 4c 8b 2b 4d 01 e5 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 87 17 e3 ff 49 83 7d 00 00 0f 85 d2 01 00 00 41
RSP: 0018:ffffc9000bfa76a8 EFLAGS: 00000246
RAX: 1ffff1100a8ea64b RBX: ffff8880276a0108 RCX: 0000000000080000
RDX: ffffc90003ed1000 RSI: 000000000000022a RDI: 000000000000022b
RBP: dffffc0000000000 R08: 0400000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c7a0 R12: 0000000000000258
R13: ffff888054753258 R14: ffffffff825479f4 R15: 1ffff11004ed4021
 scm_recv_one_fd+0x17f/0x210 net/core/scm.c:375
 scm_detach_fds+0x215/0x6b0 net/core/scm.c:397
 scm_recv_unix+0x122/0x420 net/core/scm.c:573
 __unix_dgram_recvmsg+0x9d6/0xd70 net/unix/af_unix.c:2669
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x196/0x1e0 net/socket.c:1173
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2933
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2975
 __sys_recvmsg net/socket.c:3008 [inline]
 __do_sys_recvmsg net/socket.c:3014 [inline]
 __se_sys_recvmsg net/socket.c:3011 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:3011
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99339e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe994198028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fe993625fa0 RCX: 00007fe99339e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fe993435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe993626038 R14: 00007fe993625fa0 R15: 00007fe99374fa48
 </TASK>
BUG: sleeping function ca
BUG: sleeping function called from invalid context at kernel/rcu/srcutree.c:1472
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6183, name: syz.1.150
preempt_count: 101, expected: 0
RCU nest depth: 0, expected: 0
locks held by syz.1.150/6183: 3, last CPU#1:
 #0: ffff888030d816f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:947 [inline]
 #1: ffffffff8ed5c7a0 (rcu_read_lock_sched){....}-{1:2}, at: fd_install+0x94/0x3d0 fs/file.c:687
 #2: ffffc90000a18cc0 ((&vub300->inactivity_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x5f0 kernel/time/timer.c:1745
Preemption disabled at:
[<ffffffff825479ed>] rcu_read_lock_sched include/linux/rcupdate.h:944 [inline]
[<ffffffff825479ed>] fd_install+0x8d/0x3d0 fs/file.c:687
CPU: 1 UID: 0 PID: 6183 Comm: syz.1.150 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9234
 __synchronize_srcu+0x1a1/0x2f0 kernel/rcu/srcutree.c:1472
 wakeup_source_remove drivers/base/power/wakeup.c:201 [inline]
 wakeup_source_unregister+0x129/0x3f0 drivers/base/power/wakeup.c:237
 mmc_host_classdev_release+0x47/0x100 drivers/mmc/core/host.c:69
 device_release+0xc4/0x1f0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x222/0x550 lib/kobject.c:737
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 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:fd_install+0x1df/0x3d0 fs/file.c:696
Code: c1 ef 03 41 80 3c 2f 00 74 08 48 89 df e8 a9 17 e3 ff 45 89 ec 49 c1 e4 03 4c 8b 2b 4d 01 e5 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 87 17 e3 ff 49 83 7d 00 00 0f 85 d2 01 00 00 41
RSP: 0018:ffffc9000bfa76a8 EFLAGS: 00000246
RAX: 1ffff1100a8ea64b RBX: ffff8880276a0108 RCX: 0000000000080000
RDX: ffffc90003ed1000 RSI: 000000000000022a RDI: 000000000000022b
RBP: dffffc0000000000 R08: 0400000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c7a0 R12: 0000000000000258
R13: ffff888054753258 R14: ffffffff825479f4 R15: 1ffff11004ed4021
 scm_recv_one_fd+0x17f/0x210 net/core/scm.c:375
 scm_detach_fds+0x215/0x6b0 net/core/scm.c:397
 scm_recv_unix+0x122/0x420 net/core/scm.c:573
 __unix_dgram_recvmsg+0x9d6/0xd70 net/unix/af_unix.c:2669
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x196/0x1e0 net/socket.c:1173
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2933
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2975
 __sys_recvmsg net/socket.c:3008 [inline]
 __do_sys_recvmsg net/socket.c:3014 [inline]
 __se_sys_recvmsg net/socket.c:3011 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:3011
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99339e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe994198028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fe993625fa0 RCX: 00007fe99339e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fe993435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe993626038 R14: 00007fe993625fa0 R15: 00007fe99374fa48
 </TASK>
ODEBUG: object ffffc90000a18a80 is NOT on stack ffffc9000bfa0000, but annotated.
------------[ cut here ]------------
1
WARNING: lib/debugobjects.c:672 at debug_object_is_on_stack lib/debugobjects.c:672 [inline], CPU#1: syz.1.150/6183
WARNING: lib/debugobjects.c:672 at lookup_object_or_alloc lib/debugobjects.c:705 [inline], CPU#1: syz.1.150/6183
WARNING: lib/debugobjects.c:672 at __debug_object_init+0x2c4/0x3c0 lib/debugobjects.c:798, CPU#1: syz.1.150/6183
Modules linked in:
CPU: 1 UID: 0 PID: 6183 Comm: syz.1.150 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:debug_object_is_on_stack lib/debugobjects.c:672 [inline]
RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:705 [inline]
RIP: 0010:__debug_object_init+0x2c4/0x3c0 lib/debugobjects.c:798
Code: cc cc cc 41 ff c7 44 89 3d 49 64 e8 15 48 c7 c1 80 9d 6d 8c 48 c7 c7 e0 9d 6d 8c 84 c0 48 0f 45 f9 48 89 de e8 cd d8 3d fc 90 <0f> 0b 90 e9 c0 fe ff ff e8 4f 1c 00 00 8b 05 61 ad 6e 0a 3b 05 5f
RSP: 0018:ffffc90000a189b8 EFLAGS: 00010046
RAX: 0000000000000050 RBX: ffffc90000a18a80 RCX: e51027a535e4f300
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffff88802a23bea0 R08: 0000000000000100 R09: 0000000000080000
R10: 0000000000008000 R11: ffffffff8ec362b8 R12: 1ffff9200014314c
R13: ffff88807814ad20 R14: dffffc0000000000 R15: 0000000000000001
FS:  00007fe9941986c0(0000) GS:ffff888124dd8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003340 CR3: 000000007ba20000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __synchronize_srcu+0x1d5/0x2f0 kernel/rcu/srcutree.c:1475
 wakeup_source_remove drivers/base/power/wakeup.c:201 [inline]
 wakeup_source_unregister+0x129/0x3f0 drivers/base/power/wakeup.c:237
 mmc_host_classdev_release+0x47/0x100 drivers/mmc/core/host.c:69
 device_release+0xc4/0x1f0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x222/0x550 lib/kobject.c:737
 call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 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:fd_install+0x1df/0x3d0 fs/file.c:696
Code: c1 ef 03 41 80 3c 2f 00 74 08 48 89 df e8 a9 17 e3 ff 45 89 ec 49 c1 e4 03 4c 8b 2b 4d 01 e5 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 87 17 e3 ff 49 83 7d 00 00 0f 85 d2 01 00 00 41
RSP: 0018:ffffc9000bfa76a8 EFLAGS: 00000246
RAX: 1ffff1100a8ea64b RBX: ffff8880276a0108 RCX: 0000000000080000
RDX: ffffc90003ed1000 RSI: 000000000000022a RDI: 000000000000022b
RBP: dffffc0000000000 R08: 0400000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c7a0 R12: 0000000000000258
R13: ffff888054753258 R14: ffffffff825479f4 R15: 1ffff11004ed4021
 scm_recv_one_fd+0x17f/0x210 net/core/scm.c:375
 scm_detach_fds+0x215/0x6b0 net/core/scm.c:397
 scm_recv_unix+0x122/0x420 net/core/scm.c:573
 __unix_dgram_recvmsg+0x9d6/0xd70 net/unix/af_unix.c:2669
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x196/0x1e0 net/socket.c:1173
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2933
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2975
 __sys_recvmsg net/socket.c:3008 [inline]
 __do_sys_recvmsg net/socket.c:3014 [inline]
 __se_sys_recvmsg net/socket.c:3011 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:3011
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe99339e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe994198028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007fe993625fa0 RCX: 00007fe99339e159
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fe993435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe993626038 R14: 00007fe993625fa0 R15: 00007fe99374fa48
 </TASK>
----------------
Code disassembly (best guess):
   0:	c1 ef 03             	shr    $0x3,%edi
   3:	41 80 3c 2f 00       	cmpb   $0x0,(%r15,%rbp,1)
   8:	74 08                	je     0x12
   a:	48 89 df             	mov    %rbx,%rdi
   d:	e8 a9 17 e3 ff       	call   0xffe317bb
  12:	45 89 ec             	mov    %r13d,%r12d
  15:	49 c1 e4 03          	shl    $0x3,%r12
  19:	4c 8b 2b             	mov    (%rbx),%r13
  1c:	4d 01 e5             	add    %r12,%r13
  1f:	4c 89 e8             	mov    %r13,%rax
  22:	48 c1 e8 03          	shr    $0x3,%rax
  26:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1)
* 2a:	74 08                	je     0x34 <-- trapping instruction
  2c:	4c 89 ef             	mov    %r13,%rdi
  2f:	e8 87 17 e3 ff       	call   0xffe317bb
  34:	49 83 7d 00 00       	cmpq   $0x0,0x0(%r13)
  39:	0f 85 d2 01 00 00    	jne    0x211
  3f:	41                   	rex.B

Crashes (67):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/06 13:15 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/06 11:31 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/05 15:13 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/05 09:14 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/04 10:06 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/04 04:50 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/09/04 01:25 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/03 21:07 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/03 15:41 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/03 14:35 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/03 02:28 upstream 940de590b839 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/02 23:30 upstream 89a312991dc6 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/02 16:55 upstream 89a312991dc6 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/02 13:06 upstream 89a312991dc6 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/02 03:37 upstream 89a312991dc6 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/30 04:55 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/28 23:29 upstream 1b78070aaef6 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/28 08:11 upstream 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/27 10:09 upstream 73e3f0710014 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/26 17:11 upstream 45c13f3f9e3b a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 19:12 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 13:22 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 13:05 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 03:55 upstream 66498c75b4f8 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 01:35 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/24 15:42 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/24 15:08 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/24 13:25 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/24 11:16 upstream 0a0d1d55dad5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/22 18:33 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/21 12:11 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/21 09:23 upstream 9328b3b03bdc 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/20 08:20 upstream a4ff2be345d0 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/20 02:42 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/20 02:05 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/19 18:45 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/19 11:11 upstream bd5f485f3f02 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/19 10:17 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 17:55 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 17:31 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 16:11 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 14:04 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 06:55 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/18 05:56 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/07 07:03 upstream df2908090cda 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/09/02 06:23 upstream 786262be6048 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/08/31 20:05 upstream cee9395acd80 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/08/31 14:09 upstream cee9395acd80 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/08/29 22:16 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/08/28 14:27 upstream 1b78070aaef6 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/08/26 15:00 upstream 45c13f3f9e3b 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: suspicious RCU usage in mmc_free_host
2026/09/03 17:55 linux-next 32b6ef9a5d0e 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/09/01 16:08 linux-next 89c07d98716a 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/26 05:11 linux-next a8406e6c0b79 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/26 04:29 linux-next a8406e6c0b79 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/26 04:17 linux-next a8406e6c0b79 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/25 19:44 linux-next a8406e6c0b79 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/21 17:29 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
2026/08/20 14:28 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mmc_free_host
2026/08/19 14:37 linux-next 6a746cd265ae 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING: suspicious RCU usage in mmc_free_host
* Struck through repros no longer work on HEAD.