linux-stable.git/drivers/md, branch v6.18.2

dm log-writes: Add missing set_freezable() for freezable kthread

2025-12-18T13:03:40+00:00

[ Upstream commit ab08f9c8b363297cafaf45475b08f78bf19b88ef ]

The log_writes_kthread() calls try_to_freeze() but lacks set_freezable(),
rendering the freeze attempt ineffective since kernel threads are
non-freezable by default. This prevents proper thread suspension during
system suspend/hibernate.

Add set_freezable() to explicitly mark the thread as freezable.

Fixes: 0e9cebe72459 ("dm: add log writes target")
Signed-off-by: Haotian Zhang 
Reviewed-by: Benjamin Marzinski 
Signed-off-by: Mikulas Patocka 
Signed-off-by: Sasha Levin

dm-raid: fix possible NULL dereference with undefined raid type

2025-12-18T13:03:40+00:00

[ Upstream commit 2f6cfd6d7cb165a7af8877b838a9f6aab4159324 ]

rs->raid_type is assigned from get_raid_type_by_ll(), which may return
NULL. This NULL value could be dereferenced later in the condition
'if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)))'.

Add a fail-fast check to return early with an error if raid_type is NULL,
similar to other uses of this function.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: 33e53f06850f ("dm raid: introduce extended superblock and new raid types to support takeover/reshaping")
Signed-off-by: Alexey Simakov 
Signed-off-by: Mikulas Patocka 
Signed-off-by: Sasha Levin

md/raid5: fix IO hang when array is broken with IO inflight

2025-12-18T13:03:28+00:00

[ Upstream commit a913d1f6a7f607c110aeef8b58c8988f47a4b24e ]

Following test can cause IO hang:

mdadm -CvR /dev/md0 -l10 -n4 /dev/sd[abcd] --assume-clean --chunk=64K --bitmap=none
sleep 5
echo 1 > /sys/block/sda/device/delete
echo 1 > /sys/block/sdb/device/delete
echo 1 > /sys/block/sdc/device/delete
echo 1 > /sys/block/sdd/device/delete

dd if=/dev/md0 of=/dev/null bs=8k count=1 iflag=direct

Root cause:

1) all disks removed, however all rdevs in the array is still in sync,
IO will be issued normally.

2) IO failure from sda, and set badblocks failed, sda will be faulty
and MD_SB_CHANGING_PENDING will be set.

3) error recovery try to recover this IO from other disks, IO will be
issued to sdb, sdc, and sdd.

4) IO failure from sdb, and set badblocks failed again, now array is
broken and will become read-only.

5) IO failure from sdc and sdd, however, stripe can't be handled anymore
because MD_SB_CHANGING_PENDING is set:

handle_stripe
 handle_stripe
 if (test_bit MD_SB_CHANGING_PENDING)
  set_bit STRIPE_HANDLE
  goto finish
  // skip handling failed stripe

release_stripe
 if (test_bit STRIPE_HANDLE)
  list_add_tail conf->hand_list

6) later raid5d can't handle failed stripe as well:

raid5d
 md_check_recovery
  md_update_sb
   if (!md_is_rdwr())
    // can't clear pending bit
    return
 if (test_bit MD_SB_CHANGING_PENDING)
  break;
  // can't handle failed stripe

Since MD_SB_CHANGING_PENDING can never be cleared for read-only array,
fix this problem by skip this checking for read-only array.

Link: https://lore.kernel.org/linux-raid/20251117085557.770572-3-yukuai@fnnas.com
Fixes: d87f064f5874 ("md: never update metadata when array is read-only.")
Signed-off-by: Yu Kuai 
Reviewed-by: Li Nan 
Signed-off-by: Sasha Levin

md: init bioset in mddev_init

2025-12-18T13:02:55+00:00

[ Upstream commit 381a3ce1c0ffed647c9b913e142b099c7e9d5afc ]

IO operations may be needed before md_run(), such as updating metadata
after writing sysfs. Without bioset, this triggers a NULL pointer
dereference as below:

 BUG: kernel NULL pointer dereference, address: 0000000000000020
 Call Trace:
  md_update_sb+0x658/0xe00
  new_level_store+0xc5/0x120
  md_attr_store+0xc9/0x1e0
  sysfs_kf_write+0x6f/0xa0
  kernfs_fop_write_iter+0x141/0x2a0
  vfs_write+0x1fc/0x5a0
  ksys_write+0x79/0x180
  __x64_sys_write+0x1d/0x30
  x64_sys_call+0x2818/0x2880
  do_syscall_64+0xa9/0x580
  entry_SYSCALL_64_after_hwframe+0x4b/0x53

Reproducer
```
  mdadm -CR /dev/md0 -l1 -n2 /dev/sd[cd]
  echo inactive > /sys/block/md0/md/array_state
  echo 10 > /sys/block/md0/md/new_level
```

mddev_init() can only be called once per mddev, no need to test if bioset
has been initialized anymore.

Link: https://lore.kernel.org/linux-raid/20251103125757.1405796-3-linan666@huaweicloud.com
Fixes: d981ed841930 ("md: Add new_level sysfs interface")
Signed-off-by: Li Nan 
Reviewed-by: Xiao Ni 
Signed-off-by: Yu Kuai 
Signed-off-by: Sasha Levin

md: delete md_redundancy_group when array is becoming inactive

2025-12-18T13:02:55+00:00

[ Upstream commit 0ce112d9171ad766d4c6716951e73f91a0bfc184 ]

'md_redundancy_group' are created in md_run() and deleted in del_gendisk(),
but these are not paired. Writing inactive/active to sysfs array_state can
trigger md_run() multiple times without del_gendisk(), leading to
duplicate creation as below:

 sysfs: cannot create duplicate filename '/devices/virtual/block/md0/md/sync_action'
 Call Trace:
  dump_stack_lvl+0x9f/0x120
  dump_stack+0x14/0x20
  sysfs_warn_dup+0x96/0xc0
  sysfs_add_file_mode_ns+0x19c/0x1b0
  internal_create_group+0x213/0x830
  sysfs_create_group+0x17/0x20
  md_run+0x856/0xe60
  ? __x64_sys_openat+0x23/0x30
  do_md_run+0x26/0x1d0
  array_state_store+0x559/0x760
  md_attr_store+0xc9/0x1e0
  sysfs_kf_write+0x6f/0xa0
  kernfs_fop_write_iter+0x141/0x2a0
  vfs_write+0x1fc/0x5a0
  ksys_write+0x79/0x180
  __x64_sys_write+0x1d/0x30
  x64_sys_call+0x2818/0x2880
  do_syscall_64+0xa9/0x580
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 md: cannot register extra attributes for md0

Creation of it depends on 'pers', its lifecycle cannot be aligned with
gendisk. So fix this issue by triggering 'md_redundancy_group' deletion
when the array is becoming inactive.

Link: https://lore.kernel.org/linux-raid/20251103125757.1405796-2-linan666@huaweicloud.com
Fixes: 790abe4d77af ("md: remove/add redundancy group only in level change")
Signed-off-by: Li Nan 
Reviewed-by: Xiao Ni 
Signed-off-by: Yu Kuai 
Signed-off-by: Sasha Levin

md: avoid repeated calls to del_gendisk

2025-12-18T13:02:53+00:00

[ Upstream commit 90e3bb44c0a86e245d8e5c6520206fa113acb1ee ]

There is a uaf problem which is found by case 23rdev-lifetime:

Oops: general protection fault, probably for non-canonical address 0xdead000000000122
RIP: 0010:bdi_unregister+0x4b/0x170
Call Trace:
 
 __del_gendisk+0x356/0x3e0
 mddev_unlock+0x351/0x360
 rdev_attr_store+0x217/0x280
 kernfs_fop_write_iter+0x14a/0x210
 vfs_write+0x29e/0x550
 ksys_write+0x74/0xf0
 do_syscall_64+0xbb/0x380
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff5250a177e

The sequence is:
1. rdev remove path gets reconfig_mutex
2. rdev remove path release reconfig_mutex in mddev_unlock
3. md stop calls do_md_stop and sets MD_DELETED
4. rdev remove path calls del_gendisk because MD_DELETED is set
5. md stop path release reconfig_mutex and calls del_gendisk again

So there is a race condition we should resolve. This patch adds a
flag MD_DO_DELETE to avoid the race condition.

Link: https://lore.kernel.org/linux-raid/20251029063419.21700-1-xni@redhat.com
Fixes: 9e59d609763f ("md: call del_gendisk in control path")
Signed-off-by: Xiao Ni 
Suggested-by: Yu Kuai 
Reviewed-by: Li Nan 
Signed-off-by: Yu Kuai 
Signed-off-by: Sasha Levin

md: fix rcu protection in md_wakeup_thread

2025-12-18T13:02:53+00:00

[ Upstream commit 0dc76205549b4c25705e54345f211b9f66e018a0 ]

We attempted to use RCU to protect the pointer 'thread', but directly
passed the value when calling md_wakeup_thread(). This means that the
RCU pointer has been acquired before rcu_read_lock(), which renders
rcu_read_lock() ineffective and could lead to a use-after-free.

Link: https://lore.kernel.org/linux-raid/20251015083227.1079009-1-yun.zhou@windriver.com
Fixes: 446931543982 ("md: protect md_thread with rcu")
Signed-off-by: Yun Zhou 
Reviewed-by: Li Nan 
Reviewed-by: Yu Kuai 
Signed-off-by: Yu Kuai 
Signed-off-by: Sasha Levin

md: delete mddev kobj before deleting gendisk kobj

2025-12-18T13:02:53+00:00

[ Upstream commit cc394b94dc40b661efc9895665abf03640ffff2d ]

In sync del gendisk path, it deletes gendisk first and the directory
/sys/block/md is removed. Then it releases mddev kobj in a delayed work.
If we enable debug log in sysfs_remove_group, we can see the debug log
'sysfs group bitmap not found for kobject md'. It's the reason that the
parent kobj has been deleted, so it can't find parent directory.

In creating path, it allocs gendisk first, then adds mddev kobj. So it
should delete mddev kobj before deleting gendisk.

Before commit 9e59d609763f ("md: call del_gendisk in control path"), it
releases mddev kobj first. If the kobj hasn't been deleted, it does clean
job and deletes the kobj. Then it calls del_gendisk and releases gendisk
kobj. So it doesn't need to call kobject_del to delete mddev kobj. After
this patch, in sync del gendisk path, the sequence changes. So it needs
to call kobject_del to delete mddev kobj.

After this patch, the sequence is:
1. kobject del mddev kobj
2. del_gendisk deletes gendisk kobj
3. mddev_delayed_delete releases mddev kobj
4. md_kobj_release releases gendisk kobj

Link: https://lore.kernel.org/linux-raid/20250928012424.61370-1-xni@redhat.com
Fixes: 9e59d609763f ("md: call del_gendisk in control path")
Signed-off-by: Xiao Ni 
Reviewed-by: Li Nan 
Signed-off-by: Yu Kuai 
Signed-off-by: Sasha Levin

dm-verity: fix unreliable memory allocation

2025-11-21T11:51:41+00:00

GFP_NOWAIT allocation may fail anytime. It needs to be changed to
GFP_NOIO. There's no need to handle an error because mempool_alloc with
GFP_NOIO can't fail.

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Reviewed-by: Eric Biggers

dm: fix failure when empty flush's bi_sector points beyond the device end

2025-11-20T18:50:42+00:00

An empty flush bio can have arbitrary bi_sector. The commit 2b1c6d7a890a
introduced a regression that device mapper would fail an empty flush bio
with -EIO if the sector pointed beyond the end of the device.

The commit introduced an optimization, that optimization would pass
flushes to __split_and_process_bio and __split_and_process_bio is not
prepared to handle empty bios. Fix this bug by passing only non-empty
flushes to __split_and_process_bio - non-empty flushes must have valid
bi_sector. Empty bios will go through __send_empty_flush, as they did
before the optimization.

This problem can be reproduced by running the lvm2 test:
make check_local T=lvconvert-thin.sh LVM_TEST_PREFER_BRD=0

Signed-off-by: Mikulas Patocka 
Fixes: 2b1c6d7a890a ("dm: optimize REQ_PREFLUSH with data when using the linear target")
Reported-by: Zdenek Kabelac 
Reviewed-by: Bart Van Assche