Bug 2373442 (CVE-2022-50126) - CVE-2022-50126 kernel: jbd2: fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted
Summary: CVE-2022-50126 kernel: jbd2: fix assertion 'jh->b_frozen_data == NULL' failur...
Keywords:
Status: NEW
Alias: CVE-2022-50126
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-06-18 12:03 UTC by OSIDB Bzimport
Modified: 2025-06-20 10:12 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2025-06-18 12:03:06 UTC
In the Linux kernel, the following vulnerability has been resolved:

jbd2: fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted

Following process will fail assertion 'jh->b_frozen_data == NULL' in
jbd2_journal_dirty_metadata():

                   jbd2_journal_commit_transaction
unlink(dir/a)
 jh->b_transaction = trans1
 jh->b_jlist = BJ_Metadata
                    journal->j_running_transaction = NULL
                    trans1->t_state = T_COMMIT
unlink(dir/b)
 handle->h_trans = trans2
 do_get_write_access
  jh->b_modified = 0
  jh->b_frozen_data = frozen_buffer
  jh->b_next_transaction = trans2
 jbd2_journal_dirty_metadata
  is_handle_aborted
   is_journal_aborted // return false

           --> jbd2 abort <--

                     while (commit_transaction->t_buffers)
                      if (is_journal_aborted)
                       jbd2_journal_refile_buffer
                        __jbd2_journal_refile_buffer
                         WRITE_ONCE(jh->b_transaction,
						jh->b_next_transaction)
                         WRITE_ONCE(jh->b_next_transaction, NULL)
                         __jbd2_journal_file_buffer(jh, BJ_Reserved)
        J_ASSERT_JH(jh, jh->b_frozen_data == NULL) // assertion failure !

The reproducer (See detail in [Link]) reports:
 ------------[ cut here ]------------
 kernel BUG at fs/jbd2/transaction.c:1629!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 2 PID: 584 Comm: unlink Tainted: G        W
 5.19.0-rc6-00115-g4a57a8400075-dirty #697
 RIP: 0010:jbd2_journal_dirty_metadata+0x3c5/0x470
 RSP: 0018:ffffc90000be7ce0 EFLAGS: 00010202
 Call Trace:
  <TASK>
  __ext4_handle_dirty_metadata+0xa0/0x290
  ext4_handle_dirty_dirblock+0x10c/0x1d0
  ext4_delete_entry+0x104/0x200
  __ext4_unlink+0x22b/0x360
  ext4_unlink+0x275/0x390
  vfs_unlink+0x20b/0x4c0
  do_unlinkat+0x42f/0x4c0
  __x64_sys_unlink+0x37/0x50
  do_syscall_64+0x35/0x80

After journal aborting, __jbd2_journal_refile_buffer() is executed with
holding @jh->b_state_lock, we can fix it by moving 'is_handle_aborted()'
into the area protected by @jh->b_state_lock.

Comment 1 Avinash Hanwate 2025-06-20 06:43:00 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061813-CVE-2022-50126-5c77@gregkh/T


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