INFO: rcu detected stall in generic_file_read_iter

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ad326970 Linux 4.19.152
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17d2176f900000
kernel config: https://syzkaller.appspot.com/x/.config?x=1ec7667b405157e
dashboard link: https://syzkaller.appspot.com/bug?extid=7a19f5db69e7dcbe3275
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a19f5...@syzkaller.appspotmail.com

MINIX-fs: mounting unchecked file system, running fsck is recommended
MINIX-fs: mounting unchecked file system, running fsck is recommended
MINIX-fs: mounting unchecked file system, running fsck is recommended
MINIX-fs: mounting unchecked file system, running fsck is recommended
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=82529, q=171)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295012061-4295001558), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor.1 R running task 24640 788 8148 0x80000000
Call Trace:
<IRQ>
sched_show_task.cold+0x332/0x396 kernel/sched/core.c:5341
print_other_cpu_stall kernel/rcu/tree.c:1430 [inline]
check_cpu_stall kernel/rcu/tree.c:1557 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0xb37/0xe19 kernel/rcu/tree.c:2682
update_process_times+0x2a/0xb0 kernel/time/timer.c:1650
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:slab_alloc mm/slab.c:3390 [inline]
RIP: 0010:kmem_cache_alloc+0x2c4/0x370 mm/slab.c:3557
Code: 00 48 c7 c7 1b 80 b7 89 e8 b9 07 a8 ff e9 b5 fd ff ff e8 af 56 cf ff 48 83 3d 4f d6 56 08 00 0f 84 ae 00 00 00 4c 89 ff 57 9d <0f> 1f 44 00 00 e9 1c fe ff ff 65 ff 05 fb 35 67 7e 48 8b 05 0c 31
RSP: 0018:ffff8880568dedb0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: 0000000000708840 RCX: 1ffff110138bbd2d
RDX: 0000000000000000 RSI: ffff88809c5de948 RDI: 0000000000000282
RBP: 0000000000708840 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888205beddc8
R13: ffff88813be45200 R14: ffff88813be45200 R15: 0000000000000282
kmem_cache_zalloc include/linux/slab.h:699 [inline]
alloc_buffer_head+0x20/0x130 fs/buffer.c:3388
alloc_page_buffers+0x169/0x5c0 fs/buffer.c:830
create_empty_buffers+0x2c/0x760 fs/buffer.c:1528
create_page_buffers+0x212/0x350 fs/buffer.c:1645
block_read_full_page+0xcf/0xd10 fs/buffer.c:2239
read_pages.isra.0+0x329/0x5d0 mm/readahead.c:133
__do_page_cache_readahead+0x5c6/0x6c0 mm/readahead.c:211
ra_submit mm/internal.h:66 [inline]
ondemand_readahead.isra.0+0x575/0xd40 mm/readahead.c:493
page_cache_async_readahead mm/readahead.c:575 [inline]
page_cache_async_readahead+0x406/0x750 mm/readahead.c:548
generic_file_buffered_read mm/filemap.c:2123 [inline]
generic_file_read_iter+0x16ac/0x2b60 mm/filemap.c:2385
call_read_iter include/linux/fs.h:1815 [inline]
new_sync_read fs/read_write.c:406 [inline]
__vfs_read+0x518/0x750 fs/read_write.c:418
integrity_kernel_read+0x147/0x1f0 security/integrity/iint.c:200
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:364 [inline]
ima_calc_file_shash security/integrity/ima/ima_crypto.c:393 [inline]
ima_calc_file_hash+0x512/0x990 security/integrity/ima/ima_crypto.c:458
ima_collect_measurement+0x4c4/0x570 security/integrity/ima/ima_api.c:231
process_measurement+0xddd/0x1440 security/integrity/ima/ima_main.c:284
ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:391
do_last fs/namei.c:3425 [inline]
path_openat+0x7e4/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa59f18cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000022140 RCX: 000000000045de59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff139adedf R14: 00007fa59f18d9c0 R15: 000000000118bf2c
rcu: rcu_preempt kthread starved for 10557 jiffies! g82529 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 29208 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1825
rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: ad326970 Linux 4.19.152
git tree: linux-4.19.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16684418500000

kernel config: https://syzkaller.appspot.com/x/.config?x=1ec7667b405157e
dashboard link: https://syzkaller.appspot.com/bug?extid=7a19f5db69e7dcbe3275
compiler: gcc (GCC) 10.1.0-syz 20200507

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=110ad664500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134a1818500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a19f5...@syzkaller.appspotmail.com

MINIX-fs: mounting unchecked file system, running fsck is recommended
MINIX-fs: mounting unchecked file system, running fsck is recommended
MINIX-fs: mounting unchecked file system, running fsck is recommended

hrtimer: interrupt took 32418 ns

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:

rcu: (detected by 0, t=10502 jiffies, g=5397, q=134)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295018525-4295008022), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor891 R running task 24656 8153 8149 0x80000000

Call Trace:
<IRQ>
sched_show_task.cold+0x332/0x396 kernel/sched/core.c:5341
print_other_cpu_stall kernel/rcu/tree.c:1430 [inline]
check_cpu_stall kernel/rcu/tree.c:1557 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0xb37/0xe19 kernel/rcu/tree.c:2682
update_process_times+0x2a/0xb0 kernel/time/timer.c:1650
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>

RIP: 0010:__read_once_size_nocheck.constprop.0+0x3/0x10 include/linux/compiler.h:211
Code: 00 75 18 48 8b 43 48 5b 5d c3 e8 a8 9d 70 00 eb a8 48 89 ef e8 2e 9e 70 00 eb c4 48 89 ef e8 24 9e 70 00 eb de 66 90 48 8b 07 <48> 89 06 c3 66 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffff8880b136e940 EFLAGS: 00000283 ORIG_RAX: ffffffffffffff13
RAX: ffffffff818356c5 RBX: 1ffff1101626dd2a RCX: 0000000000000000
RDX: ffff8880b136eb10 RSI: ffff8880b136e970 RDI: ffff8880b136f248
RBP: ffff8880b136f248 R08: ffffffff8b97f2d6 R09: ffffffff8b97f2d7
R10: 0000000000074071 R11: 0000000000000001 R12: ffff8880b136eac8
R13: ffff8880b136eb10 R14: ffff8880b1368000 R15: ffff8880b136eac8
deref_stack_reg arch/x86/kernel/unwind_orc.c:341 [inline]
deref_stack_reg+0x134/0x1d0 arch/x86/kernel/unwind_orc.c:335
unwind_next_frame+0xec4/0x1c60 arch/x86/kernel/unwind_orc.c:509
__save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44
save_stack mm/kasan/kasan.c:448 [inline]
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553
kmem_cache_alloc+0x122/0x370 mm/slab.c:3559

RIP: 0033:0x4456e9
Code: 5d cc fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 2b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd6321e1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004456e9

RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0

RBP: 00000000006d0018 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004027a0
R13: 0000000000402830 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10581 jiffies! g5397 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0

rcu: RCU grace-period kthread stack dump:

rcu_preempt R running task 29128 10 2 0x80000000