<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/md/md.c, branch linux-4.19.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>md: clean up invalid BUG_ON in md_ioctl</title>
<updated>2024-09-04T11:13:02+00:00</updated>
<author>
<name>Li Nan</name>
<email>linan122@huawei.com</email>
</author>
<published>2024-02-26T03:14:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5c11581df1f58c43ce8b2e9c14184ab1f75c883f'/>
<id>5c11581df1f58c43ce8b2e9c14184ab1f75c883f</id>
<content type='text'>
[ Upstream commit 9dd8702e7cd28ebf076ff838933f29cf671165ec ]

'disk-&gt;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 &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240226031444.3606764-4-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9dd8702e7cd28ebf076ff838933f29cf671165ec ]

'disk-&gt;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 &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240226031444.3606764-4-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: Don't clear MD_CLOSING when the raid is about to stop</title>
<updated>2024-03-26T22:22:34+00:00</updated>
<author>
<name>Li Nan</name>
<email>linan122@huawei.com</email>
</author>
<published>2024-02-26T03:14:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8eea2ea62b459cebffd20d5d5121becbec838291'/>
<id>8eea2ea62b459cebffd20d5d5121becbec838291</id>
<content type='text'>
[ Upstream commit 9674f54e41fffaf06f6a60202e1fa4cc13de3cf5 ]

The raid should not be opened anymore when it is about to be stopped.
However, other processes can open it again if the flag MD_CLOSING is
cleared before exiting. From now on, this flag will not be cleared when
the raid will be stopped.

Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
Signed-off-by: Li Nan &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240226031444.3606764-6-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9674f54e41fffaf06f6a60202e1fa4cc13de3cf5 ]

The raid should not be opened anymore when it is about to be stopped.
However, other processes can open it again if the flag MD_CLOSING is
cleared before exiting. From now on, this flag will not be cleared when
the raid will be stopped.

Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
Signed-off-by: Li Nan &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20240226031444.3606764-6-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: implement -&gt;set_read_only to hook into BLKROSET processing</title>
<updated>2024-03-26T22:22:34+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-11-03T10:00:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bde70d747f81f7f014b7c63d6a7b2dd6c8356f43'/>
<id>bde70d747f81f7f014b7c63d6a7b2dd6c8356f43</id>
<content type='text'>
[ Upstream commit 118cf084adb3964d06e1667cf7d702e56e5cd2c5 ]

Implement the -&gt;set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 9674f54e41ff ("md: Don't clear MD_CLOSING when the raid is about to stop")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 118cf084adb3964d06e1667cf7d702e56e5cd2c5 ]

Implement the -&gt;set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 9674f54e41ff ("md: Don't clear MD_CLOSING when the raid is about to stop")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: switch to -&gt;check_events for media change notifications</title>
<updated>2024-03-26T22:22:34+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-07-08T12:25:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc51c01a3d5a796e18520a186f56e13f8e70749f'/>
<id>dc51c01a3d5a796e18520a186f56e13f8e70749f</id>
<content type='text'>
[ Upstream commit a564e23f0f99759f453dbefcb9160dec6d99df96 ]

md is the last driver using the legacy media_changed method.  Switch
it over to (not so) new -&gt;clear_events approach, which also removes the
need for the -&gt;revalidate_disk method.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
[axboe: remove unused 'bdops' variable in disk_clear_events()]
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 9674f54e41ff ("md: Don't clear MD_CLOSING when the raid is about to stop")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a564e23f0f99759f453dbefcb9160dec6d99df96 ]

md is the last driver using the legacy media_changed method.  Switch
it over to (not so) new -&gt;clear_events approach, which also removes the
need for the -&gt;revalidate_disk method.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
[axboe: remove unused 'bdops' variable in disk_clear_events()]
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 9674f54e41ff ("md: Don't clear MD_CLOSING when the raid is about to stop")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: Whenassemble the array, consult the superblock of the freshest device</title>
<updated>2024-02-23T07:12:48+00:00</updated>
<author>
<name>Alex Lyakas</name>
<email>alex.lyakas@zadara.com</email>
</author>
<published>2023-12-13T12:24:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=81ca80caa3c5c2e4e5d1da2dca42cc11964c1e9f'/>
<id>81ca80caa3c5c2e4e5d1da2dca42cc11964c1e9f</id>
<content type='text'>
[ 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 &lt;alex.lyakas@zadara.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;alex.lyakas@zadara.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: fix data corruption for raid456 when reshape restart while grow up</title>
<updated>2023-08-11T09:45:25+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-05-12T01:56:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8fede6cfbd0d08daf2eb52329c8592ae15d544b1'/>
<id>8fede6cfbd0d08daf2eb52329c8592ae15d544b1</id>
<content type='text'>
[ Upstream commit 873f50ece41aad5c4f788a340960c53774b5526e ]

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

echo frozen &gt; sync_action
echo reshape &gt; 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 &lt;reddunur@online.de&gt;
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 873f50ece41aad5c4f788a340960c53774b5526e ]

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

echo frozen &gt; sync_action
echo reshape &gt; 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 &lt;reddunur@online.de&gt;
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid10: fix wrong setting of max_corr_read_errors</title>
<updated>2023-08-11T09:45:02+00:00</updated>
<author>
<name>Li Nan</name>
<email>linan122@huawei.com</email>
</author>
<published>2023-05-22T07:25:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=025fde32fb957a5c271711bc66841f817ff5f299'/>
<id>025fde32fb957a5c271711bc66841f817ff5f299</id>
<content type='text'>
[ 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 &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230522072535.1523740-3-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;linan122@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230522072535.1523740-3-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid10: fix overflow of md/safe_mode_delay</title>
<updated>2023-08-11T09:45:02+00:00</updated>
<author>
<name>Li Nan</name>
<email>linan122@huawei.com</email>
</author>
<published>2023-05-22T07:25:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=239029f961e33be13471e916ba12842998fabec1'/>
<id>239029f961e33be13471e916ba12842998fabec1</id>
<content type='text'>
[ 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 &lt; 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 &lt;linan122@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230522072535.1523740-2-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt; 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 &lt;linan122@huawei.com&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20230522072535.1523740-2-linan666@huaweicloud.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: avoid signed overflow in slot_store()</title>
<updated>2023-04-05T09:15:39+00:00</updated>
<author>
<name>NeilBrown</name>
<email>neilb@suse.de</email>
</author>
<published>2023-03-05T22:36:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b7de906cf91457c655edb0cb734df5a19f970ed3'/>
<id>b7de906cf91457c655edb0cb734df5a19f970ed3</id>
<content type='text'>
[ 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 &lt;error27@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;error27@gmail.com&gt;
Signed-off-by: NeilBrown &lt;neilb@suse.de&gt;
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: fix a crash in mempool_free</title>
<updated>2023-01-18T10:30:40+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2022-11-04T13:53:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b5be563b4356b3089b3245d024cae3f248ba7090'/>
<id>b5be563b4356b3089b3245d024cae3f248ba7090</id>
<content type='text'>
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(&amp;mddev-&gt;pending_writes) and
  wake_up(&amp;mddev-&gt;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 &lt;48&gt; 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:
  &lt;TASK&gt;
  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
  &lt;/TASK&gt;
 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 &lt;mpatocka@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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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(&amp;mddev-&gt;pending_writes) and
  wake_up(&amp;mddev-&gt;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 &lt;48&gt; 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:
  &lt;TASK&gt;
  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
  &lt;/TASK&gt;
 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 &lt;mpatocka@redhat.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
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