In the Linux kernel, the following vulnerability has been resolved:
jbd2: check 'jh->b_transaction' before removing it from checkpoint
Following process will corrupt ext4 image:
Step 1:
jbd2_journal_commit_transaction
__jbd2_journal_insert_checkpoint(jh, commit_transaction)
// Put jh into trans1->t_checkpoint_list
journal->j_checkpoint_transactions = commit_transaction
// Put trans1 into journal->j_checkpoint_transactions
Step 2:
do_get_write_access
test_clear_buffer_dirty(bh) // clear buffer dirty,set jbd dirty
__jbd2_journal_file_buffer(jh, transaction) // jh belongs to trans2
Step 3:
drop_cache
journal_shrink_one_cp_list
jbd2_journal_try_remove_checkpoint
if (!trylock_buffer(bh)) // lock bh, true
if (buffer_dirty(bh)) // buffer is not dirty
__jbd2_journal_remove_checkpoint(jh)
// remove jh from trans1->t_checkpoint_list
Step 4:
jbd2_log_do_checkpoint
trans1 = journal->j_checkpoint_transactions
// jh is not in trans1->t_checkpoint_list
jbd2_cleanup_journal_tail(journal) // trans1 is done
Step 5: Power cut, trans2 is not committed, jh is lost in next mounting.
Fix it by checking 'jh->b_transaction' before remove it from checkpoint.
jbd2: check 'jh->b_transaction' before removing it from checkpoint
Following process will corrupt ext4 image:
Step 1:
jbd2_journal_commit_transaction
__jbd2_journal_insert_checkpoint(jh, commit_transaction)
// Put jh into trans1->t_checkpoint_list
journal->j_checkpoint_transactions = commit_transaction
// Put trans1 into journal->j_checkpoint_transactions
Step 2:
do_get_write_access
test_clear_buffer_dirty(bh) // clear buffer dirty,set jbd dirty
__jbd2_journal_file_buffer(jh, transaction) // jh belongs to trans2
Step 3:
drop_cache
journal_shrink_one_cp_list
jbd2_journal_try_remove_checkpoint
if (!trylock_buffer(bh)) // lock bh, true
if (buffer_dirty(bh)) // buffer is not dirty
__jbd2_journal_remove_checkpoint(jh)
// remove jh from trans1->t_checkpoint_list
Step 4:
jbd2_log_do_checkpoint
trans1 = journal->j_checkpoint_transactions
// jh is not in trans1->t_checkpoint_list
jbd2_cleanup_journal_tail(journal) // trans1 is done
Step 5: Power cut, trans2 is not committed, jh is lost in next mounting.
Fix it by checking 'jh->b_transaction' before remove it from checkpoint.
Metrics
Affected Vendors & Products
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 01 Oct 2025 12:00:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Description | In the Linux kernel, the following vulnerability has been resolved: jbd2: check 'jh->b_transaction' before removing it from checkpoint Following process will corrupt ext4 image: Step 1: jbd2_journal_commit_transaction __jbd2_journal_insert_checkpoint(jh, commit_transaction) // Put jh into trans1->t_checkpoint_list journal->j_checkpoint_transactions = commit_transaction // Put trans1 into journal->j_checkpoint_transactions Step 2: do_get_write_access test_clear_buffer_dirty(bh) // clear buffer dirty,set jbd dirty __jbd2_journal_file_buffer(jh, transaction) // jh belongs to trans2 Step 3: drop_cache journal_shrink_one_cp_list jbd2_journal_try_remove_checkpoint if (!trylock_buffer(bh)) // lock bh, true if (buffer_dirty(bh)) // buffer is not dirty __jbd2_journal_remove_checkpoint(jh) // remove jh from trans1->t_checkpoint_list Step 4: jbd2_log_do_checkpoint trans1 = journal->j_checkpoint_transactions // jh is not in trans1->t_checkpoint_list jbd2_cleanup_journal_tail(journal) // trans1 is done Step 5: Power cut, trans2 is not committed, jh is lost in next mounting. Fix it by checking 'jh->b_transaction' before remove it from checkpoint. | |
Title | jbd2: check 'jh->b_transaction' before removing it from checkpoint | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-01T11:46:11.862Z
Reserved: 2025-10-01T11:39:39.407Z
Link: CVE-2023-53526

No data.

Status : Received
Published: 2025-10-01T12:15:57.177
Modified: 2025-10-01T12:15:57.177
Link: CVE-2023-53526

No data.

No data.