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: 538d, last: 27d

Cause bisection: the bug happens on the oldest tested release
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	403d	444d	0/3	public: reported syz repro on 2019/04/23 08:58
linux-4.14	INFO: rcu detected stall in ext4_file_write_iter	C	7	13d	455d	0/1	upstream: reported C repro on 2019/04/12 16:30
linux-4.19	INFO: rcu detected stall in ext4_file_write_iter	C	7	27d	447d	0/1	upstream: reported C repro on 2019/04/20 13:09

Sample crash report:

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6221, q=39)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295053756-4295043253), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor551 R  running task    22976  8244   8242 0x00004000
Call Trace:
 <IRQ>
 sched_show_task+0x3bd/0x490 kernel/sched/core.c:5286
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:536 [inline]
 rcu_pending kernel/rcu/tree.c:2625 [inline]
 rcu_sched_clock_irq+0x1607/0x1740 kernel/rcu/tree.c:2161
 update_process_times+0x134/0x190 kernel/time/timer.c:1639
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x257/0x410 kernel/time/tick-sched.c:1298
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x471/0x8b0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 smp_apic_timer_interrupt+0xee/0x260 arch/x86/kernel/apic/apic.c:1066
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806
 </IRQ>
RIP: 0010:__find_get_block+0x235/0x1080 fs/buffer.c:1294
Code: fc ff df 80 3c 08 00 74 0c 48 c7 c7 a0 63 aa 88 e8 a0 a6 e8 ff 48 83 3d 08 2f e4 06 00 0f 84 d9 0d 00 00 fb 66 0f 1f 44 00 00 <48> 85 db 74 50 e8 41 7d af ff 48 89 df e8 d9 d6 ff ff 49 89 de 48
RSP: 0018:ffff888097faedd8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1154c74 RBX: ffff88809137abd0 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffff88808ee6ade8 RDI: ffff88808ee6ad68
RBP: ffff888097faee38 R08: ffff88808ee6ad80 R09: ffffed101226f587
R10: ffffed101226f587 R11: 1ffff1101226f586 R12: 0000000000031528
R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000001
 __getblk_gfp+0x30/0x9c0 fs/buffer.c:1318
 sb_getblk include/linux/buffer_head.h:325 [inline]
 __ext4_get_inode_loc+0x37b/0xcb0 fs/ext4/inode.c:4594
 ext4_get_inode_loc fs/ext4/inode.c:4707 [inline]
 ext4_reserve_inode_write+0xe9/0x220 fs/ext4/inode.c:5888
 ext4_mark_inode_dirty+0x102/0x790 fs/ext4/inode.c:6040
 ext4_dirty_inode+0x8b/0xb0 fs/ext4/inode.c:6079
 __mark_inode_dirty+0xbf/0x700 fs/fs-writeback.c:2161
 mark_inode_dirty include/linux/fs.h:2137 [inline]
 __generic_write_end fs/buffer.c:2118 [inline]
 generic_write_end+0x151/0x320 fs/buffer.c:2162
 ext4_da_write_end+0x72e/0x8a0 fs/ext4/inode.c:3201
 generic_perform_write+0x3ac/0x550 mm/filemap.c:3217
 __generic_file_write_iter+0x24b/0x520 mm/filemap.c:3335
 ext4_file_write_iter+0x902/0x12e0 fs/ext4/file.c:266
 do_iter_readv_writev+0x6f5/0x9c0 include/linux/fs.h:1866
 do_iter_write+0x180/0x590 fs/read_write.c:970
 vfs_iter_write+0x7c/0xa0 fs/read_write.c:983
 iter_file_splice_write+0x79f/0xf40 fs/splice.c:746
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0xf7/0x130 fs/splice.c:1020
 splice_direct_to_actor+0x4c6/0xb40 fs/splice.c:975
 do_splice_direct+0x279/0x3d0 fs/splice.c:1063
 do_sendfile+0x8a3/0x1110 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1519 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x13b/0x220 fs/read_write.c:1511
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4417c9
Code: e8 7c e7 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 bb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffda91c5b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ffda91c5ce0 RCX: 00000000004417c9
RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00008080fffffffe R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004024a0 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10566 jiffies! g6221 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    26336    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:2818 [inline]
 __schedule+0x658/0x9e0 kernel/sched/core.c:3445
 schedule+0x131/0x1d0 kernel/sched/core.c:3509
 schedule_timeout+0x19d/0x2b0 kernel/time/timer.c:1807
 rcu_gp_fqs_loop kernel/rcu/tree.c:1589 [inline]
 rcu_gp_kthread+0xfd8/0x1880 kernel/rcu/tree.c:1746
 kthread+0x325/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Fix bisection attempts:
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-smack-root	2020/05/21 03:02	upstream	b85051e7	34bf9440	.config	log	report	syz	C

Crashes (82):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-smack-root	2019/06/22 20:00	upstream	abf02e29	34bf9440	.config	log	report	syz	C	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
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-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-linux-next-kasan-gce-root	2019/06/30 05:07	linux-next	48568d8c	7509bf36	.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-selinux-root	2020/05/23 21:45	upstream	423b8baf	9682898d	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2020/04/21 02:39	upstream	ae83d0b4	98a9f9e6	.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	2020/04/18 08:08	upstream	95988fbc	435c6d53	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-root	2020/04/02 21:11	upstream	7be97138	a34e2c33	.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	2020/03/26 03:05	upstream	1b649e0b	e8e6c7d2	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-selinux-root	2020/03/19 18:23	upstream	cd607737	2c31c529	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-root	2020/03/11 09:50	upstream	e9414845	35f53e45	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2020/03/04 15:44	upstream	63623fd4	c88c7b75	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-selinux-root	2020/02/28 07:43	upstream	f8788d86	59b57593	.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	2020/02/17 15:26	upstream	11a48a5a	2b411596	.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	2020/02/17 12:56	upstream	11a48a5a	2b411596	.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	2020/02/15 22:49	upstream	829e6944	5d7b90f1	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-smack-root	2020/02/12 14:36	upstream	359c92c0	84f4fc8a	.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	2020/02/12 03:58	upstream	359c92c0	a75b198c	.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	2020/02/11 15:39	upstream	0a679e13	4d1ab643	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2020/02/03 23:16	upstream	754beeec	93e5e335	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-root	2020/01/12 22:47	upstream	6327edce	31290a45	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-smack-root	2020/01/08 02:23	upstream	ae608821	6738e0b3	.config	log	report			akpm@linux-foundation.org, cgroups@vger.kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, vdavydov.dev@gmail.com
ci-upstream-kasan-gce-smack-root	2020/01/08 01:13	upstream	ae608821	6738e0b3	.config	log	report			akpm@linux-foundation.org, christian@brauner.io, keescook@chromium.org, linux-kernel@vger.kernel.org, luto@amacapital.net, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, wad@chromium.org
ci-upstream-kasan-gce-root	2019/12/25 18:45	upstream	46cf053e	be5c2c81	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2019/12/21 11:32	upstream	6398b9fc	bc586918	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-kasan-gce-smack-root	2019/12/03 09:47	upstream	596cf45c	ab342da3	.config	log	report			akpm@linux-foundation.org, cgroups@vger.kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, vdavydov.dev@gmail.com
ci-upstream-kasan-gce-smack-root	2019/12/02 23:38	upstream	596cf45c	ab342da3	.config	log	report			aarcange@redhat.com, akpm@linux-foundation.org, christian@brauner.io, christian@kellner.me, cyphar@cyphar.com, elena.reshetova@intel.com, jgg@ziepe.ca, keescook@chromium.org, ldv@altlinux.org, linux-kernel@vger.kernel.org, luto@amacapital.net, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, viro@zeniv.linux.org.uk, wad@chromium.org
ci-upstream-kasan-gce-root	2019/07/20 15:14	upstream	abdfd52a	1656845f	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/06/20 07:02	upstream	abf02e29	34bf9440	.config	log	report			linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2019/06/14 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	2019/03/25 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-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-linux-next-kasan-gce-root	2020/06/13 19:36	linux-next	e7b08814	dbce178a	.config	log	report			fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de
ci-upstream-linux-next-kasan-gce-root	2020/06/13 06:12	linux-next	e7b08814	f4724dd3	.config	log	report			fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de
ci-upstream-linux-next-kasan-gce-root	2020/04/14 14:59	linux-next	f19bb13a	3f3c5574	.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	2020/03/09 22:00	linux-next	770fbb32	35f53e45	.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	2020/02/18 07:04	linux-next	c25a951c	1ce142dc	.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	2020/02/16 03:06	linux-next	9f01828e	5d7b90f1	.config	log	report			akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
ci-upstream-linux-next-kasan-gce-root	2020/02/06 18:46	linux-next	a0c61bf1	c91cbc9d	.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	2019/07/20 01:36	linux-next	6d21a41b	1656845f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/07/02 08:57	linux-next	48a8a5f9	cccc4302	.config	log	report			akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, hannes@cmpxchg.org, hughd@google.com, josef@toxicpanda.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org
ci-upstream-linux-next-kasan-gce-root	2019/06/23 05:58	linux-next	dc636f5d	34bf9440	.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	2019/06/17 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