From: Li Lingfeng <lilingfeng3@huawei.com>
To: <dm-devel@redhat.com>
Cc: <agk@redhat.com>, <snitzer@kernel.org>,
<linux-kernel@vger.kernel.org>, <houtao1@huawei.com>,
<yi.zhang@huawei.com>, <yukuai3@huawei.com>,
<lilingfeng3@huawei.com>
Subject: [PATCH] dm thin: check fail_io before using data_sm
Date: Tue, 6 Jun 2023 20:20:24 +0800 [thread overview]
Message-ID: <20230606122024.1965040-1-lilingfeng3@huawei.com> (raw)
We should 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
dm_block_manager_create
↓
// create failed
__destroy_persistent_data_objects
dm_sm_destroy(pmd->data_sm)
↓
// free data_sm
dm_sm_dec_blocks
↓
// try to access pmd->data_sm --> UAF
As shown above, if dm_pool_commit_metadata() and dm_block_manager_create()
fail in pool_message process, kworker may trigger UAF.
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
---
drivers/md/dm-thin-metadata.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 9f5cb52c5763..b9461faa9f0d 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -1756,13 +1756,15 @@ 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;
@@ -1770,10 +1772,11 @@ int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *re
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;
@@ -1781,10 +1784,11 @@ 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);
- 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;
--
2.31.1
reply other threads:[~2023-06-06 12:22 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230606122024.1965040-1-lilingfeng3@huawei.com \
--to=lilingfeng3@huawei.com \
--cc=agk@redhat.com \
--cc=dm-devel@redhat.com \
--cc=houtao1@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=snitzer@kernel.org \
--cc=yi.zhang@huawei.com \
--cc=yukuai3@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®