mainline inclusion from mainline-v6.4-rc8 commit cb65b282c9640c27d3129e2e04b711ce1b352838 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7FITX CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h...

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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

Conflicts: drivers/md/dm-thin-metadata.c Signed-off-by: Li Lingfeng lilingfeng3@huawei.com --- v1->v2: do not change default return value of dm_pool_inc_data_range and dm_pool_dec_data_range

drivers/md/dm-thin-metadata.c | 36 ++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 85e80fc17641..69401bfac76e 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1771,13 +1771,15 @@ int dm_thin_remove_range(struct dm_thin_device *td,

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; @@ -1788,10 +1790,14 @@ int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_ int r = 0;

pmd_write_lock(pmd); - for (; b != e; b++) { - r = dm_sm_inc_block(pmd->data_sm, b); - if (r) - break; + if (!pmd->fail_io) { + for (; b != e; b++) { + r = dm_sm_inc_block(pmd->data_sm, b); + if (r) + break; + } + } else { + r = -EINVAL; } pmd_write_unlock(pmd);

@@ -1800,13 +1806,17 @@ int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_

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); - for (; b != e; b++) { - r = dm_sm_dec_block(pmd->data_sm, b); - if (r) - break; + if (!pmd->fail_io) { + for (; b != e; b++) { + r = dm_sm_dec_block(pmd->data_sm, b); + if (r) + break; + } + } else { + r = -EINVAL; } pmd_write_unlock(pmd);