kernel.git/drivers/md/dm-thin-metadata.c, branch linux-5.8.y

dm thin metadata: Fix use-after-free in dm_bm_set_read_only

2020-09-09T17:14:32Z

commit 3a653b205f29b3f9827a01a0c88bfbcb0d169494 upstream. The following error ocurred when testing disk online/offline: [ 301.798344] device-mapper: thin: 253:5: aborting current metadata transaction [ 301.848441] device-mapper: thin: 253:5: failed to abort metadata transaction [ 301.849206] Aborting journal on device dm-26-8. [ 301.850489] EXT4-fs error (device dm-26) in __ext4_new_inode:943: Journal has aborted [ 301.851095] EXT4-fs (dm-26): Delayed block allocation failed for inode 398742 at logical offset 181 with max blocks 19 with error 30 [ 301.854476] BUG: KASAN: use-after-free in dm_bm_set_read_only+0x3a/0x40 [dm_persistent_data] Reason is: metadata_operation_failed abort_transaction dm_pool_abort_metadata __create_persistent_data_objects r = __open_or_format_metadata if (r) --> If failed will free pmd->bm but pmd->bm not set NULL dm_block_manager_destroy(pmd->bm); set_pool_mode dm_pool_metadata_read_only(pool->pmd); dm_bm_set_read_only(pmd->bm); --> use-after-free Add checks to see if pmd->bm is NULL in dm_bm_set_read_only and dm_bm_set_read_write functions. If bm is NULL it means creating the bm failed and so dm_bm_is_read_only must return true. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm thin metadata: Avoid returning cmd->bm wild pointer on error

2020-09-09T17:14:32Z

commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream. Maybe __create_persistent_data_objects() caller will use PTR_ERR as a pointer, it will lead to some strange things. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm thin metadata: fix lockdep complaint

2020-02-27T17:00:53Z

[ 3934.173244] ====================================================== [ 3934.179572] WARNING: possible circular locking dependency detected [ 3934.185884] 5.4.21-xfstests #1 Not tainted [ 3934.190151] ------------------------------------------------------ [ 3934.196673] dmsetup/8897 is trying to acquire lock: [ 3934.201688] ffffffffbce82b18 (shrinker_rwsem){++++}, at: unregister_shrinker+0x22/0x80 [ 3934.210268] but task is already holding lock: [ 3934.216489] ffff92a10cc5e1d0 (&pmd->root_lock){++++}, at: dm_pool_metadata_close+0xba/0x120 [ 3934.225083] which lock already depends on the new lock. [ 3934.564165] Chain exists of: shrinker_rwsem --> &journal->j_checkpoint_mutex --> &pmd->root_lock For a more detailed lockdep report, please see: https://lore.kernel.org/r/20200220234519.GA620489@mit.edu We shouldn't need to hold the lock while are just tearing down and freeing the whole metadata pool structure. Fixes: 44d8ebf436399a4 ("dm thin metadata: use pool locking at end of dm_pool_metadata_close") Signed-off-by: Theodore Ts'o Signed-off-by: Mike Snitzer

dm thin metadata: use pool locking at end of dm_pool_metadata_close

2020-01-15T01:22:49Z

Ensure that the pool is locked during calls to __commit_transaction and __destroy_persistent_data_objects. Just being consistent with locking, but reality is dm_pool_metadata_close is called once pool is being destroyed so access to pool shouldn't be contended. Also, use pmd_write_lock_in_core rather than __pmd_write_lock in dm_pool_commit_metadata and rename __pmd_write_lock to pmd_write_lock_in_core -- there was no need for the alias. In addition, verify that the pool is locked in __commit_transaction(). Fixes: 873f258becca ("dm thin metadata: do not write metadata if no changes occurred") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

dm thin metadata: Fix trivial math error in on-disk format documentation

2020-01-07T17:07:31Z

Signed-off-by: Jeffle Xu Signed-off-by: Mike Snitzer

dm thin metadata: use true/false for bool variable

2020-01-07T17:07:24Z

Fixes coccicheck warning: drivers/md/dm-thin-metadata.c:814:3-14: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1109:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1621:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1652:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1706:1-12: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot Signed-off-by: zhengbin Signed-off-by: Mike Snitzer

dm thin metadata: Add support for a pre-commit callback

2019-12-05T22:05:24Z

Add support for one pre-commit callback which is run right before the metadata are committed. This allows the thin provisioning target to run a callback before the metadata are committed and is required by the next commit. Cc: stable@vger.kernel.org Signed-off-by: Nikos Tsironis Acked-by: Joe Thornber Signed-off-by: Mike Snitzer

dm thin metadata: check if in fail_io mode when setting needs_check

2019-07-02T19:50:08Z

Check if in fail_io mode at start of dm_pool_metadata_set_needs_check(). Otherwise dm_pool_metadata_set_needs_check()'s superblock_lock() can crash in dm_bm_write_lock() while accessing the block manager object that was previously destroyed as part of a failed dm_pool_abort_metadata() that ultimately set fail_io to begin with. Also, update DMERR() message to more accurately describe superblock_lock() failure. Cc: stable@vger.kernel.org Reported-by: Zdenek Kabelac Signed-off-by: Mike Snitzer

dm thin metadata: do not write metadata if no changes occurred

2019-04-18T20:18:34Z

Otherwise, just activating a thin-pool and thin device and then deactivating them will cause the thin-pool metadata to be changed (e.g. superblock written) -- even without any metadata being changed. Add 'in_service' flag to struct dm_pool_metadata and set it in pmd_write_lock() because all on-disk metadata changes must take a write lock of pmd->root_lock. Once 'in_service' is set it is never cleared. __commit_transaction() will return 0 if 'in_service' is not set. dm_pool_commit_metadata() is updated to use __pmd_write_lock() so that it isn't the sole reason for putting a thin-pool in service. Also fix dm_pool_commit_metadata() to open the next transaction if the return from __commit_transaction() is 0. Not seeing why the early return ever made since for a return of 0 given that dm-io's async_io(), as used by bufio, always returns 0. Signed-off-by: Mike Snitzer

dm thin metadata: add wrappers for managing write locking of metadata

2019-04-18T20:18:34Z

No functional change, but this prepares to hook off of pmd_write_lock() with additional functionality (as provided in next commit). Suggested-by: Joe Thornber Signed-off-by: Mike Snitzer