This is a note to let you know that I've just added the patch titled
dm thin metadata: check fail_io before using data_sm
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-thin-metadata-check-fail_io-before-using-data_sm.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cb65b282c9640c27d3129e2e04b711ce1b352838 Mon Sep 17 00:00:00 2001
From: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
Date: Tue, 6 Jun 2023 20:20:24 +0800
Subject: dm thin metadata: check fail_io before using data_sm
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From: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Li Lingfeng <lilingfeng3@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -1778,13 +1778,15 @@ 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;
@@ -1792,10 +1794,11 @@ 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;
@@ -1803,10 +1806,11 @@ 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;
Patches currently in stable-queue which might be from lilingfeng3@xxxxxxxxxx are
queue-5.15/dm-thin-metadata-check-fail_io-before-using-data_sm.patch
