linux-stable.git/drivers/md/raid10.c, branch linux-4.9.y

md-raid10: fix KASAN warning

2022-08-25T09:09:24+00:00

commit d17f744e883b2f8d13cca252d71cfe8ace346f7d upstream.

There's a KASAN warning in raid10_remove_disk when running the lvm
test lvconvert-raid-reshape.sh. We fix this warning by verifying that the
value "number" is valid.

BUG: KASAN: slab-out-of-bounds in raid10_remove_disk+0x61/0x2a0 [raid10]
Read of size 8 at addr ffff889108f3d300 by task mdX_raid10/124682

CPU: 3 PID: 124682 Comm: mdX_raid10 Not tainted 5.19.0-rc6 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 
 dump_stack_lvl+0x34/0x44
 print_report.cold+0x45/0x57a
 ? __lock_text_start+0x18/0x18
 ? raid10_remove_disk+0x61/0x2a0 [raid10]
 kasan_report+0xa8/0xe0
 ? raid10_remove_disk+0x61/0x2a0 [raid10]
 raid10_remove_disk+0x61/0x2a0 [raid10]
Buffer I/O error on dev dm-76, logical block 15344, async page read
 ? __mutex_unlock_slowpath.constprop.0+0x1e0/0x1e0
 remove_and_add_spares+0x367/0x8a0 [md_mod]
 ? super_written+0x1c0/0x1c0 [md_mod]
 ? mutex_trylock+0xac/0x120
 ? _raw_spin_lock+0x72/0xc0
 ? _raw_spin_lock_bh+0xc0/0xc0
 md_check_recovery+0x848/0x960 [md_mod]
 raid10d+0xcf/0x3360 [raid10]
 ? sched_clock_cpu+0x185/0x1a0
 ? rb_erase+0x4d4/0x620
 ? var_wake_function+0xe0/0xe0
 ? psi_group_change+0x411/0x500
 ? preempt_count_sub+0xf/0xc0
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? __lock_text_start+0x18/0x18
 ? raid10_sync_request+0x36c0/0x36c0 [raid10]
 ? preempt_count_sub+0xf/0xc0
 ? _raw_spin_unlock_irqrestore+0x19/0x40
 ? del_timer_sync+0xa9/0x100
 ? try_to_del_timer_sync+0xc0/0xc0
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? __lock_text_start+0x18/0x18
 ? _raw_spin_unlock_irq+0x11/0x24
 ? __list_del_entry_valid+0x68/0xa0
 ? finish_wait+0xa3/0x100
 md_thread+0x161/0x260 [md_mod]
 ? unregister_md_personality+0xa0/0xa0 [md_mod]
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? prepare_to_wait_event+0x2c0/0x2c0
 ? unregister_md_personality+0xa0/0xa0 [md_mod]
 kthread+0x148/0x180
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x1f/0x30
 

Allocated by task 124495:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x80/0xa0
 setup_conf+0x140/0x5c0 [raid10]
 raid10_run+0x4cd/0x740 [raid10]
 md_run+0x6f9/0x1300 [md_mod]
 raid_ctr+0x2531/0x4ac0 [dm_raid]
 dm_table_add_target+0x2b0/0x620 [dm_mod]
 table_load+0x1c8/0x400 [dm_mod]
 ctl_ioctl+0x29e/0x560 [dm_mod]
 dm_compat_ctl_ioctl+0x7/0x20 [dm_mod]
 __do_compat_sys_ioctl+0xfa/0x160
 do_syscall_64+0x90/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40
 __kasan_record_aux_stack+0x9e/0xc0
 kvfree_call_rcu+0x84/0x480
 timerfd_release+0x82/0x140
L __fput+0xfa/0x400
 task_work_run+0x80/0xc0
 exit_to_user_mode_prepare+0x155/0x160
 syscall_exit_to_user_mode+0x12/0x40
 do_syscall_64+0x42/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40
 __kasan_record_aux_stack+0x9e/0xc0
 kvfree_call_rcu+0x84/0x480
 timerfd_release+0x82/0x140
 __fput+0xfa/0x400
 task_work_run+0x80/0xc0
 exit_to_user_mode_prepare+0x155/0x160
 syscall_exit_to_user_mode+0x12/0x40
 do_syscall_64+0x42/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

The buggy address belongs to the object at ffff889108f3d200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
 256-byte region [ffff889108f3d200, ffff889108f3d300)

The buggy address belongs to the physical page:
page:000000007ef2a34c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1108f3c
head:000000007ef2a34c order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=2)
raw: 4000000000010200 0000000000000000 dead000000000001 ffff889100042b40
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff889108f3d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff889108f3d280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff889108f3d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff889108f3d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff889108f3d400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

md: Fix failed allocation of md_register_thread

2019-03-23T12:19:53+00:00

commit e406f12dde1a8375d77ea02d91f313fb1a9c6aec upstream.

mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang 
Signed-off-by: Aditya Pakki 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

It's wrong to add len to sector_nr in raid10 reshape twice

2019-03-19T12:14:11+00:00

commit b761dcf1217760a42f7897c31dcb649f59b2333e upstream.

In reshape_request it already adds len to sector_nr already. It's wrong to add len to
sector_nr again after adding pages to bio. If there is bad block it can't copy one chunk
at a time, it needs to goto read_more. Now the sector_nr is wrong. It can cause data
corruption.

Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Xiao Ni 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

MD: fix invalid stored role for a disk - try2

2018-11-13T19:17:05+00:00

commit 9e753ba9b9b405e3902d9f08aec5f2ea58a0c317 upstream.

Commit d595567dc4f0 (MD: fix invalid stored role for a disk) broke linear
hotadd. Let's only fix the role for disks in raid1/10.
Based on Guoqing's original patch.

Reported-by: kernel test robot 
Cc: Gioh Kim 
Cc: Guoqing Jiang 
Signed-off-by: Shaohua Li 
Signed-off-by: Greg Kroah-Hartman

RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0

2018-10-10T06:53:19+00:00

[ Upstream commit 1d0ffd264204eba1861865560f1f7f7a92919384 ]

In raid10 reshape_request it gets max_sectors in read_balance. If the underlayer disks
have bad blocks, the max_sectors is less than last. It will call goto read_more many
times. It calls raise_barrier(conf, sectors_done != 0) every time. In this condition
sectors_done is not 0. So the value passed to the argument force of raise_barrier is
true.

In raise_barrier it checks conf->barrier when force is true. If force is true and
conf->barrier is 0, it panic. In this case reshape_request submits bio to under layer
disks. And in the callback function of the bio it calls lower_barrier. If the bio
finishes before calling raise_barrier again, it can trigger the BUG_ON.

Add one pair of raise_barrier/lower_barrier to fix this bug.

Signed-off-by: Xiao Ni 
Suggested-by: Neil Brown 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

md/raid10: fix that replacement cannot complete recovery after reassemble

2018-08-24T11:12:33+00:00

[ Upstream commit bda3153998f3eb2cafa4a6311971143628eacdbc ]

During assemble, the spare marked for replacement is not checked.
conf->fullsync cannot be updated to be 1. As a result, recovery will
treat it as a clean array. All recovering sectors are skipped. Original
device is replaced with the not-recovered spare.

mdadm -C /dev/md0 -l10 -n4 -pn2 /dev/loop[0123]
mdadm /dev/md0 -a /dev/loop4
mdadm /dev/md0 --replace /dev/loop0
mdadm -S /dev/md0 # stop array during recovery

mdadm -A /dev/md0 /dev/loop[01234]

After reassemble, you can see recovery go on, but it completes
immediately. In fact, recovery is not actually processed.

To solve this problem, we just add the missing logics for replacment
spares. (In raid1.c or raid5.c, they have already been checked.)

Reported-by: Alex Chen 
Reviewed-by: Alex Wu 
Reviewed-by: Chung-Chiang Cheng 
Signed-off-by: BingJing Chang 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

md: fix a potential deadlock of raid5/raid10 reshape

2018-05-30T05:50:31+00:00

[ Upstream commit 8876391e440ba615b10eef729576e111f0315f87 ]

There is a potential deadlock if mount/umount happens when
raid5_finish_reshape() tries to grow the size of emulated disk.

How the deadlock happens?
1) The raid5 resync thread finished reshape (expanding array).
2) The mount or umount thread holds VFS sb->s_umount lock and tries to
   write through critical data into raid5 emulated block device. So it
   waits for raid5 kernel thread handling stripes in order to finish it
   I/Os.
3) In the routine of raid5 kernel thread, md_check_recovery() will be
   called first in order to reap the raid5 resync thread. That is,
   raid5_finish_reshape() will be called. In this function, it will try
   to update conf and call VFS revalidate_disk() to grow the raid5
   emulated block device. It will try to acquire VFS sb->s_umount lock.
The raid5 kernel thread cannot continue, so no one can handle mount/
umount I/Os (stripes). Once the write-through I/Os cannot be finished,
mount/umount will not release sb->s_umount lock. The deadlock happens.

The raid5 kernel thread is an emulated block device. It is responible to
handle I/Os (stripes) from upper layers. The emulated block device
should not request any I/Os on itself. That is, it should not call VFS
layer functions. (If it did, it will try to acquire VFS locks to
guarantee the I/Os sequence.) So we have the resync thread to send
resync I/O requests and to wait for the results.

For solving this potential deadlock, we can put the size growth of the
emulated block device as the final step of reshape thread.

2017/12/29:
Thanks to Guoqing Jiang ,
we confirmed that there is the same deadlock issue in raid10. It's
reproducible and can be fixed by this patch. For raid10.c, we can remove
the similar code to prevent deadlock as well since they has been called
before.

Reported-by: Alex Wu 
Reviewed-by: Alex Wu 
Reviewed-by: Chung-Chiang Cheng 
Signed-off-by: BingJing Chang 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

md raid10: fix NULL deference in handle_write_completed()

2018-05-30T05:50:28+00:00

[ Upstream commit 01a69cab01c184d3786af09e9339311123d63d22 ]

In the case of 'recover', an r10bio with R10BIO_WriteError &
R10BIO_IsRecover will be progressed by handle_write_completed().
This function traverses all r10bio->devs[copies].
If devs[m].repl_bio != NULL, it thinks conf->mirrors[dev].replacement
is also not NULL. However, this is not always true.

When there is an rdev of raid10 has replacement, then each r10bio
->devs[m].repl_bio != NULL in conf->r10buf_pool. However, in 'recover',
even if corresponded replacement is NULL, it doesn't clear r10bio
->devs[m].repl_bio, resulting in replacement NULL deference.

This bug was introduced when replacement support for raid10 was
added in Linux 3.3.

As NeilBrown suggested:
	Elsewhere the determination of "is this device part of the
	resync/recovery" is made by resting bio->bi_end_io.
	If this is end_sync_write, then we tried to write here.
	If it is NULL, then we didn't try to write.

Fixes: 9ad1aefc8ae8 ("md/raid10:  Handle replacement devices during resync.")
Cc: stable (V3.3+)
Suggested-by: NeilBrown 
Signed-off-by: Yufen Yu 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

md/raid10: reset the 'first' at the end of loop

2018-04-08T10:12:59+00:00

commit 6f287ca6046edd34ed83aafb7f9033c9c2e809e2 upstream.

We need to set "first = 0' at the end of rdev_for_each
loop, so we can get the array's min_offset_diff correctly
otherwise min_offset_diff just means the last rdev's
offset diff.

[only the first chunk, due to b506335e5d2b ("md/raid10: skip spare disk as
'first' disk") being already applied - gregkh]

Suggested-by: NeilBrown 
Signed-off-by: Guoqing Jiang 
Reviewed-by: NeilBrown 
Signed-off-by: Shaohua Li 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

md/raid10: skip spare disk as 'first' disk

2018-03-24T10:00:20+00:00

[ Upstream commit b506335e5d2b4ec687dde392a3bdbf7601778f1d ]

Commit 6f287ca(md/raid10: reset the 'first' at the end of loop) ignores
a case in reshape, the first rdev could be a spare disk, which shouldn't
be accounted as the first disk since it doesn't include the offset info.

Fix: 6f287ca(md/raid10: reset the 'first' at the end of loop)
Cc: Guoqing Jiang 
Cc: NeilBrown 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman