kernel/git/stable/linux-stable.git/drivers/md, branch linux-6.6.y

md/raid1: don't set array_frozen in raid1_takeover()

2026-09-14T11:29:39+00:00

[ Upstream commit dc386aa0ac0a3ec06c9a3ea9b064b073fb72a916 ] raid1_takeover() sets conf->array_frozen = 1 on the newly-allocated r1conf and nothing ever clears it, so every I/O to the array stalls permanently once _wait_barrier() sees it stuck at 1. This used to be harmless: level_store() called mddev_resume() right after pers->run(), which called raid1_quiesce(mddev, 0) and cleared array_frozen back to 0 regardless of what raid1_takeover() set. Commit b39f35ebe86d ("md: don't quiesce in mddev_suspend()") removed that quiesce(mddev, 0) call, so the pre-set now sticks. setup_conf() already zero-initializes the new r1conf via kzalloc, so just don't set array_frozen here. Same class of bug as commit 892da88d1cd9 ("md/raid10: fix a 'conf->barrier' leakage in raid10_takeover()"), also triggered by b39f35ebe86d. Fixes: b39f35ebe86d ("md: don't quiesce in mddev_suspend()") Link: https://issues.redhat.com/browse/RHEL-191802 Signed-off-by: Bruce Johnston Link: https://patch.msgid.link/20260803180240.1177104-1-bjohnsto@redhat.com Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md: avoid stale clone I/O accounting timestamps

2026-09-14T11:29:39+00:00

[ Upstream commit 45102fc8330525d35675b1c193242bba101df5ee ] md_clone_bio() always allocates the clone from mddev->io_clone_set, even when queue I/O stats are disabled. In that case it does not call bio_start_io_acct(), but it also left md_io_clone->start_time untouched. The clone private data comes from a mempool and can contain data from a previous user. md_end_clone_io() checks start_time to decide whether it needs to call bio_end_io_acct(), so a stale non-zero value can make the completion path end accounting that was never started for this bio. Set start_time to 0 in the no-stats branch. This keeps the end path tied to whether bio_start_io_acct() actually ran. Fixes: c687297b8845 ("md: also clone new io if io accounting is disabled") Tested-by: Mykola Marzhan Link: https://patch.msgid.link/20260802195038.164272-8-yukuai@kernel.org Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md/raid5: round bitmap stripes with sector division

2026-09-14T11:29:39+00:00

[ Upstream commit 17ea021ae74987d6064c8195c4922fa025753892 ] raid5_bitmap_sector_map() aligns the array range to full RAID5 stripe widths before converting it to component sectors. That width is chunk_sectors multiplied by the number of data disks, and it is not always a power of two. Reproduce with a 4-disk RAID5, 1024-sector chunks, and three data disks. The full-stripe width is 3072 sectors. For a one-sector write at array sector 3072, correct rounding gives array range [3072, 6144), which maps to component range [1024, 2048). The old round_down()/round_up() logic instead gives [1024, 4096), which maps to [0, 1024). Use sector_div() based arithmetic so the rounded range is aligned to the actual RAID5 stripe width. The deterministic mapper test now reports the fixed component range as [1024, 2048), while the old mask-based range was [0, 1024). Fixes: 9c89f604476c ("md/raid5: implement pers->bitmap_sector()") Reported-by: Mykola Marzhan Link: https://lore.kernel.org/all/20260726185916.2223460-1-mykola@meshstor.io/ Tested-by: Mykola Marzhan Link: https://patch.msgid.link/20260802195038.164272-6-yukuai@kernel.org Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md/raid5-ppl: fix use-after-free in ppl_do_flush()

2026-09-14T11:29:28+00:00

[ Upstream commit 371f7a1b392edc8b7cf449cc7713179b588f2d0e ] The loop in ppl_do_flush() continues iterating after calling ppl_io_unit_finished(), touching io->pending_flushes and leading to a use-after-free. Add a break statement to stop the loop once io is freed. Fixes: 1532d9e87e8b ("raid5-ppl: PPL support for disks with write-back cache enabled") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/ajJF2wKYWRk4GGCK@stanley.mountain/ Signed-off-by: Sajal Gupta Reviewed-by: Yu Kuai Link: https://patch.msgid.link/20260622142146.56637-1-sajal2005gupta@gmail.com Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md/raid5: protect bitmap batch counters aka seq_flush/seq_write consistency

2026-09-14T11:29:28+00:00

[ Upstream commit f565925810cb8bc799421485770e15d922ef766a ] kcsan detect race : - raid5d() closes the current bitmap batch by updating conf->seq_flush under conf->device_lock. - __add_stripe_bio() read conf->seq_flush without that lock when assigning sh->bm_seq. so, protect seq_flush/seq_write consistency for multiple CPUs by READ_ONCE()/WRITE_ONCE() under the path without held device_lock. re-explain the stripe batch sequence number update flow: 1. sh->bm_seq declare which batch number the stripe belongs to when perform bitmap-related write. ==> bm_seq = seq_flush+1 2. stripe be handled, * if sh->bm_seq - conf->seq_write > 0, means the batch stripes **newer than** the last written batch, it cannot proceed yet, queued on bitmap_list. * otherwise , has already proceed. 3. raid5d() `++seq_flush` to closes the current batch, means * no more stripes join that old batch * just-closed batch ready to write-out to disk 4. raid5d() calls bitmap hooks unplug() or writeout, then, `++seq_write` to the same as bm_seq. - seq_flush - for producer, to close batches. - seq_write - for consumer, the checkpoint number. the report: ==================================== BUG: KCSAN: data-race in __add_stripe_bio / raid5d write to 0xffff88ba5625d470 of 4 bytes by task 82401 on cpu 0: raid5d+0x1d9/0xba0 [.....] read to 0xffff88ba5625d470 of 4 bytes by task 82421 on cpu 8: __add_stripe_bio+0x332/0x400 raid5_make_request+0x6ac/0x2930 md_handle_request+0x4a2/0xa40 md_submit_bio+0x109/0x1a0 __submit_bio+0x2ec/0x390 [.....] Fixes: 7c13edc87510 ("md: incorporate new plugging into raid5.") v1 -> v2: - remove WRITE_ONCE(conf->seq_write) in held device_lock path. - remove READ_ONCE(conf->seq_flush) in held device_lock path. Signed-off-by: Chen Cheng Reviewed-by: Yu Kuai Link: https://patch.msgid.link/20260622124649.1780233-1-chencheng@fnnas.com Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

md/md-bitmap: fix wrong bitmap_limit for clustermd when write sb

2026-09-14T11:28:56+00:00

[ Upstream commit 6130825f34d41718c98a9b1504a79a23e379701e ] In clustermd, separate write-intent-bitmaps are used for each cluster node: 0 4k 8k 12k ------------------------------------------------------------------- | idle | md super | bm super [0] + bits | | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] | | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits | | bm bits [3, contd] | | | So in node 1, pg_index in __write_sb_page() could equal to bitmap->storage.file_pages. Then bitmap_limit will be calculated to 0. md_super_write() will be called with 0 size. That means the first 4k sb area of node 1 will never be updated through filemap_write_page(). This bug causes hang of mdadm/clustermd_tests/01r1_Grow_resize. Here use (pg_index % bitmap->storage.file_pages) to make calculation of bitmap_limit correct. Fixes: ab99a87542f1 ("md/md-bitmap: fix writing non bitmap pages") Signed-off-by: Su Yue Reviewed-by: Heming Zhao Link: https://lore.kernel.org/linux-raid/20250303033918.32136-1-glass.su@suse.com Signed-off-by: Yu Kuai Signed-off-by: Sasha Levin

dm: fix resume-vs-remove race

2026-09-14T11:28:40+00:00

commit 44b43ec132f1cf3275ecc182d0c82f50c3c4c3d5 upstream. If the user issues the resume ioctl and the remove ioctl at the same time, it may be possible that the device is resumed after it is suspended in __dm_destroy. The result is that the table is destroyed without calling the postsuspend method. Dm targets expect that they may be removed only after the postsuspend method method was called. If we break this expectation, it can cause misbehavior in various targets. For example - in the dm-integrity target, the reboot notifier is not unregistered, leading to use-after-free. Fix this bug by refusing to resume if the device is being destroyed. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

dm: fix race when loading and unloading a table

2026-09-14T11:28:40+00:00

commit 5380c7f6335cc6d77eb77d065105e81155c4d9d3 upstream. If the userspace calls two concurrent table load ioctls and one of them succeeds and the other fails, there is a race condition because dm_setup_md_queue walks &md->table_devices without any lock. If the walk races with dm_table_destroy -> free_devices -> dm_put_table_device, there is access to invalid memory. Fix this race by extending the lock over the list walk. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

dm-switch: use WRITE_ONCE() in switch_region_table_write()

2026-09-14T11:28:36+00:00

commit c7391ebe33162c7962b313caea4d8e6b0bc2a671 upstream. switch_region_table_read() accesses the region table with READ_ONCE() and is called from the lockless switch_map() IO path. However, switch_region_table_write() stores to the same array with a plain assignment. This results in an inconsistent access pattern for a lockless shared variable and may trigger data race reports. Use WRITE_ONCE() to pair with the existing READ_ONCE() in switch_region_table_read(). Cc: stable@vger.kernel.org Fixes: 99eb1908e643 ("dm switch: factor out switch_region_table_read") Signed-off-by: Haotian Zhang Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman

dm-stats: fix a crash if allocation of per-cpu data fails

2026-09-14T11:28:36+00:00

commit cc87e26d9cce22061dc21e51e11afef29dbbc36a upstream. If "dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu))" fails, the code jumps to the "out" label and calls dm_stat_free. dm_stat_free does "for_each_possible_cpu(cpu) { dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);", which crashes with NULL pointer dereference if s->stat_percpu[cpu] is NULL. This commit fixes the bug by testing s->stat_percpu[cpu] for NULL before using it. Reported-by: Junzhe Yu Signed-off-by: Mikulas Patocka Fixes: fd2ed4d25270 ("dm: add statistics support") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman