This is a note to let you know that I've just added the patch titled
dm thin metadata: Fix use-after-free in dm_bm_set_read_only
to the 4.19-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-fix-use-after-free-in-dm_bm_set_read_only.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3a653b205f29b3f9827a01a0c88bfbcb0d169494 Mon Sep 17 00:00:00 2001
From: Ye Bin <yebin10@xxxxxxxxxx>
Date: Tue, 1 Sep 2020 14:25:44 +0800
Subject: dm thin metadata: Fix use-after-free in dm_bm_set_read_only
From: Ye Bin <yebin10@xxxxxxxxxx>
commit 3a653b205f29b3f9827a01a0c88bfbcb0d169494 upstream.
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@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: xiejingfeng <xiejingfeng@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-thin-metadata.c | 2 +-
drivers/md/persistent-data/dm-block-manager.c | 14 ++++++++------
2 files changed, 9 insertions(+), 7 deletions(-)
--- 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_poo
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",
--- 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_man
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_bloc
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_mana
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);
Patches currently in stable-queue which might be from yebin10@xxxxxxxxxx are
queue-4.19/dm-thin-metadata-fix-use-after-free-in-dm_bm_set_read_only.patch
