In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix race between searching chunks and release journal_head from buffer_head
Encountered a race between ocfs2_test_bg_bit_allocatable() and
jbd2_journal_put_journal_head() resulting in the below vmcore.
  PID: 106879  TASK: ffff880244ba9c00  CPU: 2   COMMAND: "loop3"
  Call trace:
    panic
    oops_end
    no_context
    __bad_area_nosemaphore
    bad_area_nosemaphore
    __do_page_fault
    do_page_fault
    page_fault
      [exception RIP: ocfs2_block_group_find_clear_bits+316]
    ocfs2_block_group_find_clear_bits [ocfs2]
    ocfs2_cluster_group_search [ocfs2]
    ocfs2_search_chain [ocfs2]
    ocfs2_claim_suballoc_bits [ocfs2]
    __ocfs2_claim_clusters [ocfs2]
    ocfs2_claim_clusters [ocfs2]
    ocfs2_local_alloc_slide_window [ocfs2]
    ocfs2_reserve_local_alloc_bits [ocfs2]
    ocfs2_reserve_clusters_with_limit [ocfs2]
    ocfs2_reserve_clusters [ocfs2]
    ocfs2_lock_refcount_allocators [ocfs2]
    ocfs2_make_clusters_writable [ocfs2]
    ocfs2_replace_cow [ocfs2]
    ocfs2_refcount_cow [ocfs2]
    ocfs2_file_write_iter [ocfs2]
    lo_rw_aio
    loop_queue_work
    kthread_worker_fn
    kthread
    ret_from_fork
When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the
bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and
released the jounal head from the buffer head.  Needed to take bit lock
for the bit 'BH_JournalHead' to fix this race.
                
            Metrics
Affected Vendors & Products
References
        History
                    Wed, 24 Sep 2025 19:15:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:* | |
| Metrics | cvssV3_1 
 | cvssV3_1 
 | 
Mon, 04 Nov 2024 12:15:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| Metrics | ssvc 
 | 
 MITRE
                        MITRE
                    Status: PUBLISHED
Assigner: Linux
Published: 2024-05-22T08:19:41.419Z
Updated: 2025-05-04T07:12:14.085Z
Reserved: 2024-05-22T06:20:56.201Z
Link: CVE-2021-47493
 Vulnrichment
                        Vulnrichment
                    Updated: 2024-08-04T05:39:59.750Z
 NVD
                        NVD
                    Status : Analyzed
Published: 2024-05-22T09:15:11.100
Modified: 2025-09-24T19:11:04.460
Link: CVE-2021-47493
 Redhat
                        Redhat