kernel/drivers/md, branch linux-5.15.y

dm mpath: make pg_init_delay_msecs settable

2026-03-04T12:20:32Z

[ Upstream commit 218b16992a37ea97b9e09b7659a25a864fb9976f ] "pg_init_delay_msecs X" can be passed as a feature in the multipath table and is used to set m->pg_init_delay_msecs in parse_features(). However, alloc_multipath_stage2(), which is called after parse_features(), resets m->pg_init_delay_msecs to its default value. Instead, set m->pg_init_delay_msecs in alloc_multipath(), which is called before parse_features(), to avoid overwriting a value passed in by the table. Signed-off-by: Benjamin Marzinski Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

md/bitmap: fix GPF in write_page caused by resize race

2026-03-04T12:20:31Z

[ Upstream commit 46ef85f854dfa9d5226b3c1c46493d79556c9589 ] A General Protection Fault occurs in write_page() during array resize: RIP: 0010:write_page+0x22b/0x3c0 [md_mod] This is a use-after-free race between bitmap_daemon_work() and __bitmap_resize(). The daemon iterates over `bitmap->storage.filemap` without locking, while the resize path frees that storage via md_bitmap_file_unmap(). `quiesce()` does not stop the md thread, allowing concurrent access to freed pages. Fix by holding `mddev->bitmap_info.mutex` during the bitmap update. Link: https://lore.kernel.org/linux-raid/20260120102456.25169-1-jinpu.wang@ionos.com Closes: https://lore.kernel.org/linux-raid/CAMGffE=Mbfp=7xD_hYxXk1PAaCZNSEAVeQGKGy7YF9f2S4=NEA@mail.gmail.com/T/#u Cc: stable@vger.kernel.org Fixes: d60b479d177a ("md/bitmap: add bitmap_resize function to allow bitmap resizing.") Signed-off-by: Jack Wang Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

dm-unstripe: fix mapping bug when there are multiple targets in a table

2026-03-04T12:20:29Z

[ Upstream commit 83c10e8dd43628d0bf86486616556cd749a3c310 ] The "unstriped" device-mapper target incorrectly calculates the sector offset on the mapped device when the target's origin is not zero. Take for example this hypothetical concatenation of the members of a two-disk RAID0: linearized: 0 2097152 unstriped 2 128 0 /dev/md/raid0 0 linearized: 2097152 2097152 unstriped 2 128 1 /dev/md/raid0 0 The intent in this example is to create a single device named /dev/mapper/linearized that comprises all of the chunks of the first disk of the RAID0 set, followed by all of the chunks of the second disk of the RAID0 set. This fails because dm-unstripe.c's map_to_core function does its computations based on the sector number within the mapper device rather than the sector number within the target. The bug turns invisible when the target's origin is at sector zero of the mapper device, as is the common case. In the example above, however, what happens is that the first half of the mapper device gets mapped correctly to the first disk of the RAID0, but the second half of the mapper device gets mapped past the end of the RAID0 device, and accesses to any of those sectors return errors. Signed-off-by: Matt Whitlock Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Fixes: 18a5bf270532 ("dm: add unstriped target") Signed-off-by: Sasha Levin

dm: clear cloned request bio pointer when last clone bio completes

2026-03-04T12:20:29Z

[ Upstream commit fb8a6c18fb9a6561f7a15b58b272442b77a242dd ] Stale rq->bio values have been observed to cause double-initialization of cloned bios in request-based device-mapper targets, leading to use-after-free and double-free scenarios. One such case occurs when using dm-multipath on top of a PCIe NVMe namespace, where cloned request bios are freed during blk_complete_request(), but rq->bio is left intact. Subsequent clone teardown then attempts to free the same bios again via blk_rq_unprep_clone(). The resulting double-free path looks like: nvme_pci_complete_batch() nvme_complete_batch() blk_mq_end_request_batch() blk_complete_request() // called on a DM clone request bio_endio() // first free of all clone bios ... rq->end_io() // end_clone_request() dm_complete_request(tio->orig) dm_softirq_done() dm_done() dm_end_request() blk_rq_unprep_clone() // second free of clone bios Fix this by clearing the clone request's bio pointer when the last cloned bio completes, ensuring that later teardown paths do not attempt to free already-released bios. Signed-off-by: Michael Liang Reviewed-by: Mohamed Khalfella Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

dm-integrity: fix a typo in the code for write/discard race

2026-03-04T12:20:28Z

[ Upstream commit c698b7f417801fcd79f0dc844250b3361d38e6b8 ] If we send a write followed by a discard, it may be possible that the discarded data end up being overwritten by the previous write from the journal. The code tries to prevent that, but there was a typo in this logic that made it not being activated as it should be. Note that if we end up here the second time (when discard_retried is true), it means that the write bio is actually racing with the discard bio, and in this situation it is not specified which of them should win. Cc: stable@vger.kernel.org Fixes: 31843edab7cb ("dm integrity: improve discard in journal mode") Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin

dm-verity: correctly handle dm_bufio_client_create() failure

2026-03-04T12:20:25Z

[ Upstream commit 119f4f04186fa4f33ee6bd39af145cdaff1ff17f ] If either of the calls to dm_bufio_client_create() in verity_fec_ctr() fails, then dm_bufio_client_destroy() is later called with an ERR_PTR() argument. That causes a crash. Fix this. Fixes: a739ff3f543a ("dm verity: add support for forward error correction") Cc: stable@vger.kernel.org Reviewed-by: Sami Tolvanen Signed-off-by: Eric Biggers Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin

dm: remove fake timeout to avoid leak request

2026-03-04T12:20:07Z

[ Upstream commit f3a9c95a15d2f4466acad5c68faeff79ca5e9f47 ] Since commit 15f73f5b3e59 ("blk-mq: move failure injection out of blk_mq_complete_request"), drivers are responsible for calling blk_should_fake_timeout() at appropriate code paths and opportunities. However, the dm driver does not implement its own timeout handler and relies on the timeout handling of its slave devices. If an io-timeout-fail error is injected to a dm device, the request will be leaked and never completed, causing tasks to hang indefinitely. Reproduce: 1. prepare dm which has iscsi slave device 2. inject io-timeout-fail to dm echo 1 >/sys/class/block/dm-0/io-timeout-fail echo 100 >/sys/kernel/debug/fail_io_timeout/probability echo 10 >/sys/kernel/debug/fail_io_timeout/times 3. read/write dm 4. iscsiadm -m node -u Result: hang task like below [ 862.243768] INFO: task kworker/u514:2:151 blocked for more than 122 seconds. [ 862.244133] Tainted: G E 6.19.0-rc1+ #51 [ 862.244337] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 862.244718] task:kworker/u514:2 state:D stack:0 pid:151 tgid:151 ppid:2 task_flags:0x4288060 flags:0x00080000 [ 862.245024] Workqueue: iscsi_ctrl_3:1 __iscsi_unbind_session [scsi_transport_iscsi] [ 862.245264] Call Trace: [ 862.245587] [ 862.245814] __schedule+0x810/0x15c0 [ 862.246557] schedule+0x69/0x180 [ 862.246760] blk_mq_freeze_queue_wait+0xde/0x120 [ 862.247688] elevator_change+0x16d/0x460 [ 862.247893] elevator_set_none+0x87/0xf0 [ 862.248798] blk_unregister_queue+0x12e/0x2a0 [ 862.248995] __del_gendisk+0x231/0x7e0 [ 862.250143] del_gendisk+0x12f/0x1d0 [ 862.250339] sd_remove+0x85/0x130 [sd_mod] [ 862.250650] device_release_driver_internal+0x36d/0x530 [ 862.250849] bus_remove_device+0x1dd/0x3f0 [ 862.251042] device_del+0x38a/0x930 [ 862.252095] __scsi_remove_device+0x293/0x360 [ 862.252291] scsi_remove_target+0x486/0x760 [ 862.252654] __iscsi_unbind_session+0x18a/0x3e0 [scsi_transport_iscsi] [ 862.252886] process_one_work+0x633/0xe50 [ 862.253101] worker_thread+0x6df/0xf10 [ 862.253647] kthread+0x36d/0x720 [ 862.254533] ret_from_fork+0x2a6/0x470 [ 862.255852] ret_from_fork_asm+0x1a/0x30 [ 862.256037] Remove the blk_should_fake_timeout() check from dm, as dm has no native timeout handling and should not attempt to fake timeouts. Signed-off-by: Ding Hui Reviewed-by: Christoph Hellwig Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin

md/raid10: fix any_working flag handling in raid10_sync_request

2026-03-04T12:19:22Z

[ Upstream commit 99582edb3f62e8ee6c34512021368f53f9b091f2 ] In raid10_sync_request(), 'any_working' indicates if any IO will be submitted. When there's only one In_sync disk with badblocks, 'any_working' might be set to 1 but no IO is submitted. Fix it by setting 'any_working' after badblock checks. Link: https://lore.kernel.org/linux-raid/20260105110300.1442509-11-linan666@huaweicloud.com Fixes: e875ecea266a ("md/raid10 record bad blocks as needed during recovery.") Signed-off-by: Li Nan Reviewed-by: Yu Kuai Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

dm-ebs: Mark full buffer dirty even on partial write

2026-01-19T12:10:01Z

commit 7fa3e7d114abc9cc71cc35d768e116641074ddb4 upstream. When performing a read-modify-write(RMW) operation, any modification to a buffered block must cause the entire buffer to be marked dirty. Marking only a subrange as dirty is incorrect because the underlying device block size(ubs) defines the minimum read/write granularity. A lower device can perform I/O only on regions which are fully aligned and sized to ubs. This change ensures that write-back operations always occur in full ubs-sized chunks, matching the intended emulation semantics of the EBS target. As for user space visible impact, submitting sub-ubs and misaligned I/O for devices which are tuned to ubs sizes only, will reject such requests, therefore it can lead to losing data. Example: 1) Create a 8K nvme device in qemu by adding -device nvme,drive=drv0,serial=foo,logical_block_size=8192,physical_block_size=8192 2) Setup dm-ebs to emulate 512B to 8K mapping urezki@pc638:~/bin$ cat dmsetup.sh lower=/dev/nvme0n1 len=$(blockdev --getsz "$lower") echo "0 $len ebs $lower 0 1 16" | dmsetup create nvme-8k urezki@pc638:~/bin$ offset 0, ebs=1 and ubs=16(in sectors). 3) Create an ext4 filesystem(default 4K block size) urezki@pc638:~/bin$ sudo mkfs.ext4 -F /dev/dm-0 mke2fs 1.47.0 (5-Feb-2023) Discarding device blocks: done Creating filesystem with 2072576 4k blocks and 518144 inodes Filesystem UUID: bd0b6ca6-0506-4e31-86da-8d22c9d50b63 Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: mkfs.ext4: Input/output error while writing out and closing file system urezki@pc638:~/bin$ dmesg [ 1618.875449] buffer_io_error: 1028 callbacks suppressed [ 1618.875456] Buffer I/O error on dev dm-0, logical block 0, lost async page write [ 1618.875527] Buffer I/O error on dev dm-0, logical block 1, lost async page write [ 1618.875602] Buffer I/O error on dev dm-0, logical block 2, lost async page write [ 1618.875620] Buffer I/O error on dev dm-0, logical block 3, lost async page write [ 1618.875639] Buffer I/O error on dev dm-0, logical block 4, lost async page write [ 1618.894316] Buffer I/O error on dev dm-0, logical block 5, lost async page write [ 1618.894358] Buffer I/O error on dev dm-0, logical block 6, lost async page write [ 1618.894380] Buffer I/O error on dev dm-0, logical block 7, lost async page write [ 1618.894405] Buffer I/O error on dev dm-0, logical block 8, lost async page write [ 1618.894427] Buffer I/O error on dev dm-0, logical block 9, lost async page write Many I/O errors because the lower 8K device rejects sub-ubs/misaligned requests. with a patch: urezki@pc638:~/bin$ sudo mkfs.ext4 -F /dev/dm-0 mke2fs 1.47.0 (5-Feb-2023) Discarding device blocks: done Creating filesystem with 2072576 4k blocks and 518144 inodes Filesystem UUID: 9b54f44f-ef55-4bd4-9e40-c8b775a616ac Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done urezki@pc638:~/bin$ sudo mount /dev/dm-0 /mnt/ urezki@pc638:~/bin$ ls -al /mnt/ total 24 drwxr-xr-x 3 root root 4096 Oct 17 15:13 . drwxr-xr-x 19 root root 4096 Jul 10 19:42 .. drwx------ 2 root root 16384 Oct 17 15:13 lost+found urezki@pc638:~/bin$ After this change: mkfs completes; mount succeeds. Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

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

2026-01-19T12:09:39Z

[ 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