syzbot


INFO: rcu detected stall in security_file_ioctl (9)

Status: upstream: reported syz repro on 2024/11/22 01:19
Subsystems: mm
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+b6f8640465bdf47ca708@syzkaller.appspotmail.com
First crash: 677d, last: 7h01m
Cause bisection: failed (error log, bisect log)
  
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ID Workflow Result Correct Bug Created Started Finished Revision Error
1b94099a-0af9-454d-9f6a-2478fde0a396 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in security_file_ioctl (9) 2026/05/26 14:50 2026/05/26 14:50 2026/05/26 15:42 76d4b4b1b168407cf701ec594f642e93a00ce699

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] INFO: rcu detected stall in security_file_ioctl (9) 0 (2) 2025/08/19 12:35
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in security_file_ioctl mm 1 7 2390d 2392d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in security_file_ioctl (2) mm 1 6 2355d 2356d 0/29 closed as invalid on 2020/01/08 05:23
upstream INFO: rcu detected stall in security_file_ioctl (7) mm 1 1 944d 944d 0/29 auto-obsoleted due to no activity on 2024/02/17 10:34
upstream INFO: rcu detected stall in security_file_ioctl (4) tomoyo 1 1 2166d 2166d 0/29 auto-closed as invalid on 2020/10/13 12:41
linux-5.15 INFO: rcu detected stall in security_file_ioctl missing-backport origin:upstream 1 syz done 16 11d 725d 0/3 upstream: reported syz repro on 2024/06/25 09:44
linux-6.6 INFO: rcu detected stall in security_file_ioctl (2) origin:lts-only 1 C inconclusive 1 13d 13d 0/2 upstream: reported C repro on 2026/06/07 05:23
upstream INFO: rcu detected stall in security_file_ioctl (8) tomoyo 1 C error done 8 719d 758d 26/29 fixed on 2024/08/06 16:46
upstream INFO: rcu detected stall in security_file_ioctl (6) kernel 1 1 1517d 1517d 0/29 auto-closed as invalid on 2022/06/24 22:52
linux-6.1 INFO: rcu detected stall in security_file_ioctl origin:upstream 1 C error 7 77d 851d 0/3 upstream: reported C repro on 2024/02/20 18:28
upstream INFO: rcu detected stall in security_file_ioctl (3) mm 1 4 2355d 2355d 0/29 closed as invalid on 2020/01/09 08:13
linux-6.6 INFO: rcu detected stall in security_file_ioctl 1 1 303d 303d 0/2 auto-obsoleted due to no activity on 2025/11/29 08:01
upstream INFO: rcu detected stall in security_file_ioctl (5) tomoyo 1 9 1613d 1852d 0/29 closed as invalid on 2022/02/08 10:00
Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/04/28 12:26 28m retest repro net-next report log
2026/04/28 09:48 1h54m retest repro net log
2026/04/28 09:48 1h39m retest repro net report log
2025/10/11 07:35 24m retest repro net report log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (3 ticks this GP) idle=bf44/1/0x4000000000000000 softirq=16213/16213 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=13025, q=669 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5950 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:649 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1231 [inline]
RIP: 0010:trace_hrtimer_cancel include/trace/events/timer.h:317 [inline]
RIP: 0010:debug_deactivate+0x44/0x1e0 kernel/time/hrtimer.c:484
Code: 3e e9 02 0f 1f 44 00 00 e8 b9 59 12 00 65 8b 1d 26 72 d1 10 bf 07 00 00 00 89 de e8 e6 5d 12 00 83 fb 07 77 5d e8 9c 59 12 00 <41> 89 de c1 eb 06 48 8d 3c dd 70 2a 82 8f be 08 00 00 00 e8 24 7c
RSP: 0018:ffffc90000007d18 EFLAGS: 00000006
RAX: ffffffff81ae9e24 RBX: 0000000000000000 RCX: ffff888025599e80
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffffc90000007e90 R08: ffffffff99b899fb R09: 1ffffffff337133f
R10: dffffc0000000000 R11: fffffbfff3371340 R12: ffff88803207f300
R13: dffffc0000000000 R14: 0000002712c90400 R15: ffff8880b86283c0
FS:  000055556c4a0500(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d1879aaa38 CR3: 0000000072e60000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1745 [inline]
 __hrtimer_run_queues+0x2b0/0xc30 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:kasan_check_byte include/linux/kasan.h:402 [inline]
RIP: 0010:lock_acquire+0x74/0x340 kernel/locking/lockdep.c:5842
Code: 84 01 00 00 89 c0 48 0f a3 05 18 3c e4 0d 73 0d e8 71 0e 09 00 84 c0 0f 84 cb 01 00 00 83 3d 32 6c e4 0d 00 0f 84 d4 00 00 00 <48> 8b b4 24 90 00 00 00 4c 89 ef e8 5c fe 88 00 83 3d 15 6c e4 0d
RSP: 0018:ffffc9000401fa40 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: ffffffff821933fd R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000401fca0 R11: fffff52000803f9e R12: 0000000000000000
R13: ffffffff8e062420 R14: 0000000000000000 R15: 0000000000000001
 fs_reclaim_acquire+0x99/0x100 mm/page_alloc.c:4318
 might_alloc include/linux/sched/mm.h:317 [inline]
 slab_pre_alloc_hook mm/slub.c:4904 [inline]
 slab_alloc_node mm/slub.c:5239 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_noprof+0x9c/0x800 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723
 security_file_ioctl+0xcb/0x2d0 security/security.c:2435
 __do_sys_ioctl fs/ioctl.c:591 [inline]
 __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b8ad8f34b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffeeac52910 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f5b8ad8f34b
RDX: 00007ffeeac52970 RSI: 0000000000008933 RDI: 0000000000000005
RBP: 00007ffeeac52970 R08: 0000000000000008 R09: 00007ffeeac529a2
R10: 00007ffeeac52da6 R11: 0000000000000246 R12: 00007ffeeac529f0
R13: 00007f5b8ae15189 R14: 00007f5b8bb14620 R15: 00007f5b8ae15189
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13025 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6636
rcu: rcu_preempt kthread starved for 10502 jiffies! g13025 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27480 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Crashes (151):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/11 15:07 net 16ce6e6fa946 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/08/19 12:35 net 864e3396976e 523f460e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/10/11 09:14 net-next 18a7e218cfcd ff1712fe .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/17 09:15 upstream 6b5a2b7d9bc1 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/15 12:36 upstream 8cd9520d35a6 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/12 12:25 upstream 2b414a95b8f7 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2026/06/08 04:33 upstream 33d8d8ec31b5 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/08 00:41 upstream c68691dc1dca cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in security_file_ioctl
2026/06/03 06:19 upstream ba3e43a9e601 3c0d2131 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/29 04:33 upstream 8fde5d1d47f6 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2026/04/14 09:43 upstream 0f0013213293 1a086e7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in security_file_ioctl
2026/03/22 12:34 upstream 113ae7b4decc 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/03/16 16:49 upstream f338e7738378 64e21424 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/03/14 03:02 upstream 1c9982b49613 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in security_file_ioctl
2026/03/11 03:31 upstream b4f0dd314b39 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/28 11:50 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2026/02/22 08:23 upstream d79526b89571 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/12 09:57 upstream c22e26bd0906 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/02 06:35 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in security_file_ioctl
2026/01/21 22:53 upstream cf38b2340c0e d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in security_file_ioctl
2026/01/20 02:19 upstream 24d479d26b25 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2026/01/17 17:31 upstream d3eeb99bbc99 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in security_file_ioctl
2025/12/25 23:17 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in security_file_ioctl
2025/12/21 22:48 upstream 9094662f6707 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2025/12/20 12:07 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2025/12/16 18:44 upstream 40fbbd64bba6 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in security_file_ioctl
2025/12/10 10:14 upstream 3d99347a2e1a d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in security_file_ioctl
2025/12/02 06:10 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in security_file_ioctl
2024/11/14 00:42 upstream f1b785f4c787 a8c99394 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in security_file_ioctl
2024/10/28 07:50 upstream 284a2f899676 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in security_file_ioctl
2025/11/21 08:14 upstream 8e621c9a3375 280ea308 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in security_file_ioctl
2026/06/20 20:35 net 96e7f9122aae 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/20 10:31 net 96e7f9122aae 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/19 10:45 net 5c121ee63568 d7ffd47b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/18 23:17 net 7d8297e26b4e a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/11 06:11 net 512db8267b73 b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/07 20:37 net 9772589b57e4 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/06/07 15:37 net 9772589b57e4 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/28 06:59 net 8ba68464e478 4c36e7e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/24 06:54 net 87a1e0fe7776 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/23 05:20 net aae9d8a5528b c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/14 20:23 net c78bdba7b966 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/13 03:30 net 9988931df99c a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/04/06 14:40 net 1caa871bb061 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/04/05 10:24 net 1caa871bb061 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/03/28 16:21 net 2edfa31769a4 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/03/20 00:49 net 55dc632ab2ac bd6dcb30 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/28 09:39 net dabffd08545f 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/25 12:13 net 1348659dc92e 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2024/11/01 21:32 net 0144c06c5890 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/05/28 18:26 net-next 0cf905cb9a12 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/02/20 03:18 net-next 8bf22c33e7a1 73a252ac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/12/01 08:43 net-next 0177f0f07886 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in security_file_ioctl
2026/04/07 16:31 linux-next cc13002a9f98 628666c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/12/30 07:17 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/12/28 08:30 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in security_file_ioctl
2025/10/20 03:44 linux-next 93f3bab4310d 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in security_file_ioctl
2025/10/27 20:56 bpf 8ce93aabbf75 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: soft lockup in security_file_ioctl
2025/04/28 03:09 bpf-next 91dbac407653 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: soft lockup in security_file_ioctl
* Struck through repros no longer work on HEAD.