linux-stable.git/drivers/md/md.c, branch linux-5.4.y

md: clean up invalid BUG_ON in md_ioctl

2024-09-04T11:14:55+00:00

[ Upstream commit 9dd8702e7cd28ebf076ff838933f29cf671165ec ]

'disk->private_data' is set to mddev in md_alloc() and never set to NULL,
and users need to open mddev before submitting ioctl. So mddev must not
have been freed during ioctl, and there is no need to check mddev here.
Clean up it.

Signed-off-by: Li Nan 
Reviewed-by: Yu Kuai 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20240226031444.3606764-4-linan666@huaweicloud.com
Signed-off-by: Sasha Levin

md: Whenassemble the array, consult the superblock of the freshest device

2024-02-23T07:24:59+00:00

[ Upstream commit dc1cc22ed58f11d58d8553c5ec5f11cbfc3e3039 ]

Upon assembling the array, both kernel and mdadm allow the devices to have event
counter difference of 1, and still consider them as up-to-date.
However, a device whose event count is behind by 1, may in fact not be up-to-date,
and array resync with such a device may cause data corruption.
To avoid this, consult the superblock of the freshest device about the status
of a device, whose event counter is behind by 1.

Signed-off-by: Alex Lyakas 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
Signed-off-by: Sasha Levin

md: fix data corruption for raid456 when reshape restart while grow up

2023-07-27T06:37:41+00:00

[ Upstream commit 873f50ece41aad5c4f788a340960c53774b5526e ]

Currently, if reshape is interrupted, echo "reshape" to sync_action will
restart reshape from scratch, for example:

echo frozen > sync_action
echo reshape > sync_action

This will corrupt data before reshape_position if the array is growing,
fix the problem by continue reshape from reshape_position.

Reported-by: Peter Neuwirth 
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin

md/raid10: fix wrong setting of max_corr_read_errors

2023-07-27T06:37:04+00:00

[ Upstream commit f8b20a405428803bd9881881d8242c9d72c6b2b2 ]

There is no input check when echo md/max_read_errors and overflow might
occur. Add check of input number.

Fixes: 1e50915fe0bb ("raid: improve MD/raid10 handling of correctable read errors.")
Signed-off-by: Li Nan 
Reviewed-by: Yu Kuai 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20230522072535.1523740-3-linan666@huaweicloud.com
Signed-off-by: Sasha Levin

md/raid10: fix overflow of md/safe_mode_delay

2023-07-27T06:37:04+00:00

[ Upstream commit 6beb489b2eed25978523f379a605073f99240c50 ]

There is no input check when echo md/safe_mode_delay in safe_delay_store().
And msec might also overflow when HZ < 1000 in safe_delay_show(), Fix it by
checking overflow in safe_delay_store() and use unsigned long conversion in
safe_delay_show().

Fixes: 72e02075a33f ("md: factor out parsing of fixed-point numbers")
Signed-off-by: Li Nan 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/20230522072535.1523740-2-linan666@huaweicloud.com
Signed-off-by: Sasha Levin

md: avoid signed overflow in slot_store()

2023-04-05T09:16:42+00:00

[ Upstream commit 3bc57292278a0b6ac4656cad94c14f2453344b57 ]

slot_store() uses kstrtouint() to get a slot number, but stores the
result in an "int" variable (by casting a pointer).
This can result in a negative slot number if the unsigned int value is
very large.

A negative number means that the slot is empty, but setting a negative
slot number this way will not remove the device from the array.  I don't
think this is a serious problem, but it could cause confusion and it is
best to fix it.

Reported-by: Dan Carpenter 
Signed-off-by: NeilBrown 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

md: fix a crash in mempool_free

2023-01-18T10:41:44+00:00

commit 341097ee53573e06ab9fc675d96a052385b851fa upstream.

There's a crash in mempool_free when running the lvm test
shell/lvchange-rebuild-raid.sh.

The reason for the crash is this:
* super_written calls atomic_dec_and_test(&mddev->pending_writes) and
  wake_up(&mddev->sb_wait). Then it calls rdev_dec_pending(rdev, mddev)
  and bio_put(bio).
* so, the process that waited on sb_wait and that is woken up is racing
  with bio_put(bio).
* if the process wins the race, it calls bioset_exit before bio_put(bio)
  is executed.
* bio_put(bio) attempts to free a bio into a destroyed bio set - causing
  a crash in mempool_free.

We fix this bug by moving bio_put before atomic_dec_and_test.

We also move rdev_dec_pending before atomic_dec_and_test as suggested by
Neil Brown.

The function md_end_flush has a similar bug - we must call bio_put before
we decrement the number of in-progress bios.

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 11557f0067 P4D 11557f0067 PUD 0
 Oops: 0002 [#1] PREEMPT SMP
 CPU: 0 PID: 73 Comm: kworker/0:1 Not tainted 6.1.0-rc3 #5
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
 Workqueue: kdelayd flush_expired_bios [dm_delay]
 RIP: 0010:mempool_free+0x47/0x80
 Code: 48 89 ef 5b 5d ff e0 f3 c3 48 89 f7 e8 32 45 3f 00 48 63 53 08 48 89 c6 3b 53 04 7d 2d 48 8b 43 10 8d 4a 01 48 89 df 89 4b 08 <48> 89 2c d0 e8 b0 45 3f 00 48 8d 7b 30 5b 5d 31 c9 ba 01 00 00 00
 RSP: 0018:ffff88910036bda8 EFLAGS: 00010093
 RAX: 0000000000000000 RBX: ffff8891037b65d8 RCX: 0000000000000001
 RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffff8891037b65d8
 RBP: ffff8891447ba240 R08: 0000000000012908 R09: 00000000003d0900
 R10: 0000000000000000 R11: 0000000000173544 R12: ffff889101a14000
 R13: ffff8891562ac300 R14: ffff889102b41440 R15: ffffe8ffffa00d05
 FS:  0000000000000000(0000) GS:ffff88942fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000001102e99000 CR4: 00000000000006b0
 Call Trace:
  
  clone_endio+0xf4/0x1c0 [dm_mod]
  clone_endio+0xf4/0x1c0 [dm_mod]
  __submit_bio+0x76/0x120
  submit_bio_noacct_nocheck+0xb6/0x2a0
  flush_expired_bios+0x28/0x2f [dm_delay]
  process_one_work+0x1b4/0x300
  worker_thread+0x45/0x3e0
  ? rescuer_thread+0x380/0x380
  kthread+0xc2/0x100
  ? kthread_complete_and_exit+0x20/0x20
  ret_from_fork+0x1f/0x30
  
 Modules linked in: brd dm_delay dm_raid dm_mod af_packet uvesafb cfbfillrect cfbimgblt cn cfbcopyarea fb font fbdev tun autofs4 binfmt_misc configfs ipv6 virtio_rng virtio_balloon rng_core virtio_net pcspkr net_failover failover qemu_fw_cfg button mousedev raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod sd_mod t10_pi crc64_rocksoft crc64 virtio_scsi scsi_mod evdev psmouse bsg scsi_common [last unloaded: brd]
 CR2: 0000000000000000
 ---[ end trace 0000000000000000 ]---

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

md: call __md_stop_writes in md_stop

2022-09-05T08:27:44+00:00

commit 0dd84b319352bb8ba64752d4e45396d8b13e6018 upstream.

From the link [1], we can see raid1d was running even after the path
raid_dtr -> md_stop -> __md_stop.

Let's stop write first in destructor to align with normal md-raid to
fix the KASAN issue.

[1]. https://lore.kernel.org/linux-raid/CAPhsuW5gc4AakdGNdF8ubpezAuDLFOYUO_sfMZcec6hQFm8nhg@mail.gmail.com/T/#m7f12bf90481c02c6d2da68c64aeed4779b7df74a

Fixes: 48df498daf62 ("md: move bitmap_destroy to the beginning of __md_stop")
Reported-by: Mikulas Patocka 
Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md: protect md_unregister_thread from reentrancy

2022-06-14T16:12:00+00:00

[ Upstream commit 1e267742283a4b5a8ca65755c44166be27e9aa0f ]

Generally, the md_unregister_thread is called with reconfig_mutex, but
raid_message in dm-raid doesn't hold reconfig_mutex to unregister thread,
so md_unregister_thread can be called simulitaneously from two call sites
in theory.

Then after previous commit which remove the protection of reconfig_mutex
for md_unregister_thread completely, the potential issue could be worse
than before.

Let's take pers_lock at the beginning of function to ensure reentrancy.

Reported-by: Donald Buczek 
Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

md: fix an incorrect NULL check in md_reload_sb

2022-06-14T16:11:47+00:00

commit 64c54d9244a4efe9bc6e9c98e13c4bbb8bb39083 upstream.

The bug is here:
	if (!rdev || rdev->desc_nr != nr) {

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each_rcu(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
found (In fact, it will be a bogus pointer to an invalid struct
object containing the HEAD). Otherwise it will bypass the check
and lead to invalid memory access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'pdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 70bcecdb1534 ("md-cluster: Improve md_reload_sb to be less error prone")
Signed-off-by: Xiaomeng Tong 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman