INFO: rcu detected stall in ext4_file_write

INFO: rcu detected stall in ext4_file_write_iter
Status: upstream: reported C repro on 2019/02/26 06:50
Reported-by: syzbot+7d19c5fe6a3f1161abb7@syzkaller.appspotmail.com
First crash: 149d, last: 2h49m

Bisection: the bug happens on the oldest tested release (bisect log)
Tree: upstream
Crash: INFO: rcu detected stall in ext4_file_write_iter (log)
Repro: C syz .config

similar bugs (3):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
android-49	INFO: rcu detected stall in ext4_file_write_iter	syz	2	14d	55d	0/3	public: reported syz repro on 2019/04/23 08:58
linux-4.14	INFO: rcu detected stall in ext4_file_write_iter		2	55d	66d	0/1	upstream: reported on 2019/04/12 16:30
linux-4.19	INFO: rcu detected stall in ext4_file_write_iter		2	4d05h	58d	0/1	upstream: reported on 2019/04/20 13:09

Sample crash report:

audit: type=1400 audit(1550814986.750:36): avc:  denied  { map } for  pid=8058 comm="syz-executor004" path="/root/syz-executor004991115" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
hrtimer: interrupt took 42841 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=5873, q=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295059997-4295049495), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor004 R  running task    26448  8069   8060 0x00000000
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5306 [inline]
 sched_show_task.cold+0x292/0x30b kernel/sched/core.c:5281
 print_other_cpu_stall kernel/rcu/tree.c:1301 [inline]
 check_cpu_stall kernel/rcu/tree.c:1429 [inline]
 rcu_pending kernel/rcu/tree.c:3018 [inline]
 rcu_check_callbacks.cold+0xa10/0xa4a kernel/rcu/tree.c:2521
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:94
Code: e5 08 41 bc f4 ff ff ff e8 11 9f ea ff 48 c7 05 12 fb e5 08 00 00 00 00 e9 c8 e9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 38 0c
RSP: 0018:ffff888084ed72c0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff88809a2205c0 RCX: ffffffff81e7c36c
RDX: 1ffff11013444114 RSI: ffffffff81e7c37a RDI: ffff88809a2208a0
RBP: ffff888084ed7300 R08: ffff88808fa28240 R09: ffffed1015d25bd0
R10: ffffed1015d25bcf R11: ffff8880ae92de7b R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 __ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline]
 ext4_dirty_inode+0x64/0xc0 fs/ext4/inode.c:6081
 __mark_inode_dirty+0x919/0x1290 fs/fs-writeback.c:2155
 mark_inode_dirty include/linux/fs.h:2125 [inline]
 __generic_write_end+0x1b9/0x240 fs/buffer.c:2118
 generic_write_end+0x6c/0x90 fs/buffer.c:2163
 ext4_da_write_end+0x3c8/0xa50 fs/ext4/inode.c:3204
 generic_perform_write+0x2f0/0x530 mm/filemap.c:3219
 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3333
 ext4_file_write_iter+0x33f/0x1160 fs/ext4/file.c:266
 call_write_iter include/linux/fs.h:1863 [inline]
 do_iter_readv_writev+0x5e0/0x8e0 fs/read_write.c:680
 do_iter_write fs/read_write.c:956 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:937
 vfs_iter_write+0x77/0xb0 fs/read_write.c:969
 iter_file_splice_write+0x667/0xbe0 fs/splice.c:749
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x126/0x1a0 fs/splice.c:1023
 splice_direct_to_actor+0x369/0x970 fs/splice.c:978
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1066
 do_sendfile+0x597/0xd00 fs/read_write.c:1436
 __do_sys_sendfile64 fs/read_write.c:1491 [inline]
 __se_sys_sendfile64 fs/read_write.c:1483 [inline]
 __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1483
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a59
Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 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 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fce454e5db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a59
RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000006dcc2c
R13: 00007ffd7bf04daf R14: 00007fce454e69c0 R15: 20c49ba5e353f7cf
rcu: rcu_preempt kthread starved for 10502 jiffies! g5873 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29200    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2844 [inline]
 __schedule+0x817/0x1cc0 kernel/sched/core.c:3485
 schedule+0x92/0x180 kernel/sched/core.c:3529
 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803
 rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline]
 rcu_gp_kthread+0x956/0x17a0 kernel/rcu/tree.c:2105
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

All crashes (40):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-selinux-root	2019/02/22 06:00	upstream	8a61716f	7ff74a98	.config	log	report	syz	C	adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-root	2019/05/03 16:28	upstream	ea986679	1bfa09b9	.config	log	report	syz	C	akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, hannes@cmpxchg.org, hughd@google.com, josef@toxicpanda.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-kasan-gce-root	2019/04/12 03:29	upstream	2d06b235	13030ef8	.config	log	report	syz	C	christian@brauner.io, ebiederm@xmission.com, jannh@google.com, keescook@chromium.org, linux-kernel@vger.kernel.org, serge@hallyn.com
ci-upstream-kasan-gce-smack-root	2019/01/19 05:29	upstream	2339e91d	2103a236	.config	log	report			akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org
ci-upstream-kasan-gce-selinux-root	2019/06/14 09:21	upstream	c11fb13a	998ccc76	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-smack-root	2019/06/14 09:19	upstream	c11fb13a	998ccc76	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-root	2019/06/14 09:19	upstream	c11fb13a	998ccc76	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2019/06/13 12:05	upstream	b076173a	3f4e812b	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2019/06/12 21:17	upstream	35110e38	794a1ad7	.config	log	report			akpm@linux-foundation.org, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, josef@toxicpanda.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-kasan-gce-root	2019/06/12 12:28	upstream	aa723548	794a1ad7	.config	log	report			akpm@linux-foundation.org, bfoster@redhat.com, dchinner@redhat.com, gthelen@google.com, jack@suse.cz, laoar.shao@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, tglx@linutronix.de, willy@infradead.org
ci-upstream-kasan-gce-root	2019/06/08 20:41	upstream	79c3ba32	0159583c	.config	log	report			john.stultz@linaro.org, linux-kernel@vger.kernel.org, sboyd@kernel.org, tglx@linutronix.de
ci-upstream-kasan-gce-smack-root	2019/06/06 19:17	upstream	156c0591	698773cb	.config	log	report			akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, josef@toxicpanda.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-kasan-gce-smack-root	2019/06/05 22:53	upstream	156c0591	bfb4a51e	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-smack-root	2019/05/08 20:44	upstream	80f23212	1ab4c999	.config	log	report			akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, josef@toxicpanda.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-kasan-gce-smack-root	2019/05/07 22:00	upstream	8ff468c2	a7383bfa	.config	log	report			christian@brauner.io, ebiederm@xmission.com, jannh@google.com, keescook@chromium.org, linux-kernel@vger.kernel.org, serge@hallyn.com
ci-upstream-kasan-gce-root	2019/04/18 11:13	upstream	e53f31bf	b0e8efcb	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2019/04/14 07:46	upstream	b60bc066	c402d8f1	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2019/04/12 15:30	upstream	2d06b235	8916f5e1	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-root	2019/04/05 17:53	upstream	ea2cec24	40f2363e	.config	log	report			akpm@linux-foundation.org, darrick.wong@oracle.com, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, josef@toxicpanda.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-kasan-gce-root	2019/04/04 14:59	upstream	145f47c7	6a475fff	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-selinux-root	2019/04/03 05:43	upstream	5e7a8ca3	dfd3394d	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-selinux-root	2019/03/26 23:36	upstream	65ae6893	55684ce1	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-smack-root	2019/03/25 05:14	upstream	8c2ffd91	2c86e0a5	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-selinux-root	2019/03/25 02:52	upstream	8c2ffd91	2c86e0a5	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-selinux-root	2019/03/24 07:56	upstream	1bdd3dbf	a2cef203	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-root	2019/03/23 06:08	upstream	fd1f297b	3361bde5	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-kasan-gce-smack-root	2019/03/02 10:48	upstream	a215ce8f	1c0e457a	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2019/02/22 02:59	upstream	8a61716f	7ff74a98	.config	log	report			akpm@linux-foundation.org, bfoster@redhat.com, dchinner@redhat.com, gthelen@google.com, jack@suse.cz, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mojha@codeaurora.org, willy@infradead.org
ci-upstream-kasan-gce-root	2019/02/19 10:23	upstream	b5372fe5	59f36113	.config	log	report			akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org
ci-upstream-linux-next-kasan-gce-root	2019/06/17 14:26	linux-next	a125097c	442206d7	.config	log	report			akpm@linux-foundation.org, bfoster@redhat.com, dchinner@redhat.com, gthelen@google.com, jack@suse.cz, laoar.shao@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mojha@codeaurora.org, rppt@linux.ibm.com, tglx@linutronix.de, tj@kernel.org, willy@infradead.org
ci-upstream-linux-next-kasan-gce-root	2019/06/12 12:28	linux-next	81a72c79	794a1ad7	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-linux-next-kasan-gce-root	2019/06/08 03:21	linux-next	3f310e51	cf9c3a50	.config	log	report			akpm@linux-foundation.org, bfoster@redhat.com, dchinner@redhat.com, gthelen@google.com, jack@suse.cz, laoar.shao@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mojha@codeaurora.org, rppt@linux.ibm.com, tglx@linutronix.de, willy@infradead.org
ci-upstream-linux-next-kasan-gce-root	2019/06/07 10:55	linux-next	3f310e51	b004e95a	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-linux-next-kasan-gce-root	2019/05/09 04:45	linux-next	31ccad9b	1ab4c999	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu
ci-upstream-linux-next-kasan-gce-root	2019/05/07 22:27	linux-next	00c3bc00	a7383bfa	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-linux-next-kasan-gce-root	2019/05/07 14:48	linux-next	fcdb095a	d28f4ce5	.config	log	report			ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, jakub.kicinski@netronome.com, john.fastabend@gmail.com, kafai@fb.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, xdp-newbies@vger.kernel.org, yhs@fb.com
ci-upstream-linux-next-kasan-gce-root	2019/05/01 15:12	linux-next	bf2c8035	618456b4	.config	log	report			bp@alien8.de, hpa@zytor.com, jannh@google.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-linux-next-kasan-gce-root	2019/04/30 12:26	linux-next	f43b05fd	20f16bef	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-linux-next-kasan-gce-root	2019/04/26 03:25	linux-next	c392798a	b617407b	.config	log	report			akpm@linux-foundation.org, darrick.wong@oracle.com, david@fromorbit.com, hannes@cmpxchg.org, hughd@google.com, josef@toxicpanda.com, jrdr.linux@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@linux.ibm.com, willy@infradead.org
ci-upstream-linux-next-kasan-gce-root	2019/04/14 07:55	linux-next	bcb67f0f	c402d8f1	.config	log	report			adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, tytso@mit.edu