From: Ye Bin yebin10@huawei.com
mainline inclusion from mainline-v5.9 commit 3a653b205f29b3f9827a01a0c88bfbcb0d169494 category: bugfix bugzilla: 41672 CVE: NA
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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 yebin10@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/md/dm-thin-metadata.c | 2 +- drivers/md/persistent-data/dm-block-manager.c | 14 ++++++++------ 2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 85077f4d257a..a6a5cee6b943 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -901,7 +901,7 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd) return -EBUSY; }
- if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) { + if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) { r = __commit_transaction(pmd); if (r < 0) DMWARN("%s: __commit_transaction() failed, error = %d", diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c index 492a3f8ac119..0401daa0f7fb 100644 --- a/drivers/md/persistent-data/dm-block-manager.c +++ b/drivers/md/persistent-data/dm-block-manager.c @@ -494,7 +494,7 @@ int dm_bm_write_lock(struct dm_block_manager *bm, void *p; int r;
- if (bm->read_only) + if (dm_bm_is_read_only(bm)) return -EPERM;
p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result); @@ -563,7 +563,7 @@ int dm_bm_write_lock_zero(struct dm_block_manager *bm, struct buffer_aux *aux; void *p;
- if (bm->read_only) + if (dm_bm_is_read_only(bm)) return -EPERM;
p = dm_bufio_new(bm->bufio, b, (struct dm_buffer **) result); @@ -603,7 +603,7 @@ EXPORT_SYMBOL_GPL(dm_bm_unlock);
int dm_bm_flush(struct dm_block_manager *bm) { - if (bm->read_only) + if (dm_bm_is_read_only(bm)) return -EPERM;
return dm_bufio_write_dirty_buffers(bm->bufio); @@ -617,19 +617,21 @@ void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
bool dm_bm_is_read_only(struct dm_block_manager *bm) { - return bm->read_only; + return (bm ? bm->read_only : true); } EXPORT_SYMBOL_GPL(dm_bm_is_read_only);
void dm_bm_set_read_only(struct dm_block_manager *bm) { - bm->read_only = true; + if (bm) + bm->read_only = true; } EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
void dm_bm_set_read_write(struct dm_block_manager *bm) { - bm->read_only = false; + if (bm) + bm->read_only = false; } EXPORT_SYMBOL_GPL(dm_bm_set_read_write);