From: Li Lingfeng lilingfeng3@huawei.com
commit cb65b282c9640c27d3129e2e04b711ce1b352838 upstream.
Must check pmd->fail_io before using pmd->data_sm since pmd->data_sm may be destroyed by other processes.
P1(kworker) P2(message) do_worker process_prepared process_prepared_discard_passdown_pt2 dm_pool_dec_data_range pool_message commit dm_pool_commit_metadata ↓ // commit failed metadata_operation_failed abort_transaction dm_pool_abort_metadata __open_or_format_metadata ↓ dm_sm_disk_open ↓ // open failed // pmd->data_sm is NULL dm_sm_dec_blocks ↓ // try to access pmd->data_sm --> UAF
As shown above, if dm_pool_commit_metadata() and dm_pool_abort_metadata() fail in pool_message process, kworker may trigger UAF.
Fixes: be500ed721a6 ("dm space maps: improve performance with inc/dec on ranges of blocks") Cc: stable@vger.kernel.org Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-thin-metadata.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
--- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1750,13 +1750,15 @@ int dm_thin_remove_range(struct dm_thin_
int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) { - int r; + int r = -EINVAL; uint32_t ref_count;
down_read(&pmd->root_lock); - r = dm_sm_get_count(pmd->data_sm, b, &ref_count); - if (!r) - *result = (ref_count > 1); + if (!pmd->fail_io) { + r = dm_sm_get_count(pmd->data_sm, b, &ref_count); + if (!r) + *result = (ref_count > 1); + } up_read(&pmd->root_lock);
return r; @@ -1764,10 +1766,11 @@ int dm_pool_block_is_shared(struct dm_po
int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) { - int r = 0; + int r = -EINVAL;
pmd_write_lock(pmd); - r = dm_sm_inc_blocks(pmd->data_sm, b, e); + if (!pmd->fail_io) + r = dm_sm_inc_blocks(pmd->data_sm, b, e); pmd_write_unlock(pmd);
return r; @@ -1775,10 +1778,11 @@ int dm_pool_inc_data_range(struct dm_poo
int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) { - int r = 0; + int r = -EINVAL;
pmd_write_lock(pmd); - r = dm_sm_dec_blocks(pmd->data_sm, b, e); + if (!pmd->fail_io) + r = dm_sm_dec_blocks(pmd->data_sm, b, e); pmd_write_unlock(pmd);
return r;