kernel/linux.git/drivers/md/md-cluster.c, branch v6.6.141

md-cluster: fix NULL pointer dereference in process_metadata_update

2026-03-04T12:20:34+00:00

[ Upstream commit f150e753cb8dd756085f46e86f2c35ce472e0a3c ] The function process_metadata_update() blindly dereferences the 'thread' pointer (acquired via rcu_dereference_protected) within the wait_event() macro. While the code comment states "daemon thread must exist", there is a valid race condition window during the MD array startup sequence (md_run): 1. bitmap_load() is called, which invokes md_cluster_ops->join(). 2. join() starts the "cluster_recv" thread (recv_daemon). 3. At this point, recv_daemon is active and processing messages. 4. However, mddev->thread (the main MD thread) is not initialized until later in md_run(). If a METADATA_UPDATED message is received from a remote node during this specific window, process_metadata_update() will be called while mddev->thread is still NULL, leading to a kernel panic. To fix this, we must validate the 'thread' pointer. If it is NULL, we release the held lock (no_new_dev_lockres) and return early, safely ignoring the update request as the array is not yet fully ready to process it. Link: https://lore.kernel.org/linux-raid/20260117145903.28921-1-jiashengjiangcool@gmail.com Signed-off-by: Jiasheng Jiang Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md/md-bitmap: add 'sync_size' into struct md_bitmap_stats

2025-02-27T12:10:44+00:00

[ Upstream commit ec6bb299c7c3dd4ca1724d13d5f5fae3ee54fc65 ] To avoid dereferencing bitmap directly in md-cluster to prepare inventing a new bitmap. BTW, also fix following checkpatch warnings: WARNING: Deprecated use of 'kmap_atomic', prefer 'kmap_local_page' instead WARNING: Deprecated use of 'kunmap_atomic', prefer 'kunmap_local' instead Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240826074452.1490072-7-yukuai1@huaweicloud.com Signed-off-by: Song Liu Stable-dep-of: 8d28d0ddb986 ("md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime") Signed-off-by: Sasha Levin

md/md-cluster: fix spares warnings for __le64

2025-02-27T12:10:44+00:00

[ Upstream commit 82697ccf7e495c1ba81e315c2886d6220ff84c2c ] drivers/md/md-cluster.c:1220:22: warning: incorrect type in assignment (different base types) drivers/md/md-cluster.c:1220:22: expected unsigned long my_sync_size drivers/md/md-cluster.c:1220:22: got restricted __le64 [usertype] sync_size drivers/md/md-cluster.c:1252:35: warning: incorrect type in assignment (different base types) drivers/md/md-cluster.c:1252:35: expected unsigned long sync_size drivers/md/md-cluster.c:1252:35: got restricted __le64 [usertype] sync_size drivers/md/md-cluster.c:1253:41: warning: restricted __le64 degrades to integer Fix the warnings by using le64_to_cpu() to convet __le64 to integer. Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240826074452.1490072-6-yukuai1@huaweicloud.com Signed-off-by: Song Liu Stable-dep-of: 8d28d0ddb986 ("md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime") Signed-off-by: Sasha Levin

md: Hold mddev->reconfig_mutex when trying to get mddev->sync_thread

2023-08-15T16:40:26+00:00

Commit ba9d9f1a707f ("Revert "md: unlock mddev before reap sync_thread in action_store"") removed the scenario of calling md_unregister_thread() without holding mddev->reconfig_mutex, so add a lock holding check before acquiring mddev->sync_thread by passing mdev to md_unregister_thread(). Signed-off-by: Li Lingfeng Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20230803071711.2546560-1-lilingfeng@huaweicloud.com Signed-off-by: Song Liu

md: protect md_thread with rcu

2023-06-13T22:25:39+00:00

Currently, there are many places that md_thread can be accessed without protection, following are known scenarios that can cause null-ptr-dereference or uaf: 1) sync_thread that is allocated and started from md_start_sync() 2) mddev->thread can be accessed directly from timeout_store() and md_bitmap_daemon_work() 3) md_unregister_thread() from action_store(). Currently, a global spinlock 'pers_lock' is borrowed to protect 'mddev->thread' in some places, this problem can be fixed likewise, however, use a global lock for all the cases is not good. Fix this problem by protecting all md_thread with rcu. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230523021017.3048783-6-yukuai1@huaweicloud.com

fs: dlm: remove DLM_LSFL_FS from uapi

2022-08-23T19:54:54+00:00

The DLM_LSFL_FS flag is set in lockspaces created directly for a kernel user, as opposed to those lockspaces created for user space applications. The user space libdlm allowed this flag to be set for lockspaces created from user space, but then used by a kernel user. No kernel user has ever used this method, so remove the ability to do it. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

md: Fix spelling mistake in comments

2022-08-02T23:14:44+00:00

There are 2 spelling mistakes in comments. Fix it. Signed-off-by: Zhang Jiaming Signed-off-by: Song Liu Signed-off-by: Jens Axboe

md: replace deprecated strlcpy & remove duplicated line

2022-04-25T21:00:36+00:00

This commit includes two topics: 1> replace deprecated strlcpy change strlcpy to strscpy for strlcpy is marked as deprecated in Documentation/process/deprecated.rst 2> remove duplicated strlcpy line in md_bitmap_read_sb@md-bitmap.c there are two duplicated strlcpy(), the history: - commit cf921cc19cf7 ("Add node recovery callbacks") introduced the first usage of strlcpy(). - commit b97e92574c0b ("Use separate bitmaps for each nodes in the cluster") introduced the second strlcpy(). this time, the two strlcpy() are same, we can remove anyone safely. - commit d3b178adb3a3 ("md: Skip cluster setup for dm-raid") added dm-raid special handling. And the "nodes" value is the key of this patch. but from this patch, strlcpy() which was introduced by b97e92574c0bf become necessary. - commit 3c462c880b52 ("md: Increment version for clustered bitmaps") used clustered major version to only handle in clustered env. this patch could look a polishment for clustered code logic. So cf921cc19cf7 became useless after d3b178adb3a3a, we could remove it safely. Signed-off-by: Heming Zhao Signed-off-by: Song Liu

md: fix spelling of "its"

2022-01-06T16:37:03+00:00

Use the possessive "its" instead of the contraction "it's" in printed messages. Signed-off-by: Randy Dunlap Cc: Song Liu Cc: linux-raid@vger.kernel.org Signed-off-by: Song Liu

Merge tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block

2020-12-16T21:09:32+00:00

Pull block driver updates from Jens Axboe: "Nothing major in here: - NVMe pull request from Christoph: - nvmet passthrough improvements (Chaitanya Kulkarni) - fcloop error injection support (James Smart) - read-only support for zoned namespaces without Zone Append (Javier González) - improve some error message (Minwoo Im) - reject I/O to offline fabrics namespaces (Victor Gladkov) - PCI queue allocation cleanups (Niklas Schnelle) - remove an unused allocation in nvmet (Amit Engel) - a Kconfig spelling fix (Colin Ian King) - nvme_req_qid simplication (Baolin Wang) - MD pull request from Song: - Fix race condition in md_ioctl() (Dae R. Jeong) - Initialize read_slot properly for raid10 (Kevin Vigor) - Code cleanup (Pankaj Gupta) - md-cluster resync/reshape fix (Zhao Heming) - Move null_blk into its own directory (Damien Le Moal) - null_blk zone and discard improvements (Damien Le Moal) - bcache race fix (Dongsheng Yang) - Set of rnbd fixes/improvements (Gioh Kim, Guoqing Jiang, Jack Wang, Lutz Pogrell, Md Haris Iqbal) - lightnvm NULL pointer deref fix (tangzhenhao) - sr in_interrupt() removal (Sebastian Andrzej Siewior) - FC endpoint security support for s390/dasd (Jan Höppner, Sebastian Ott, Vineeth Vijayan). From the s390 arch guys, arch bits included as it made it easier for them to funnel the feature through the block driver tree. - Follow up fixes (Colin Ian King)" * tag 'for-5.11/drivers-2020-12-14' of git://git.kernel.dk/linux-block: (64 commits) block: drop dead assignments in loop_init() sr: Remove in_interrupt() usage in sr_init_command(). sr: Switch the sector size back to 2048 if sr_read_sector() changed it. cdrom: Reset sector_size back it is not 2048. drivers/lightnvm: fix a null-ptr-deref bug in pblk-core.c null_blk: Move driver into its own directory null_blk: Allow controlling max_hw_sectors limit null_blk: discard zones on reset null_blk: cleanup discard handling null_blk: Improve implicit zone close null_blk: improve zone locking block: Align max_hw_sectors to logical blocksize null_blk: Fail zone append to conventional zones null_blk: Fix zone size initialization bcache: fix race between setting bdev state to none and new write request direct to backing block/rnbd: fix a null pointer dereference on dev->blk_symlink_name block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name block/rnbd: call kobject_put in the failure path Documentation/ABI/rnbd-srv: add document for force_close block/rnbd-srv: close a mapped device from server side. ...