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Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-47493MEDIUM
Linux Linux — ocfs2: fix race between searching chunks and release journal_head from buffer_head
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   H   L   N  U  N  N  H    4.7   .0017    7.0     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    ccd979bdbce9fba8412beb3f1de68a9d0171b12c –  —
  Linux    2.6.16 –                                    5.10.77
TIMELINE
  May 22  Reserved by Linux
  May 22  Published (CNA: Linux)
  Aug 4   RESCORED — CVE-2021-47493 (Linux). CVSS 7.8 → 4.7 (NVD).
CWE-362 · CNA: Linux · CVSS v3.1 · 3 references · NVD status: Modified

Description

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.

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
May 22, 2024ReservedReserved by Linux
May 22, 2024PublishedPublished (CNA: Linux)
August 4, 2026RESCOREDRESCORED — CVE-2021-47493 (Linux). CVSS 7.8 → 4.7 (NVD).

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinuxccd979bdbce9fba8412beb3f1de68a9d0171b12c
LinuxLinux2.6.165.10.77

Weaknesses

CWE-362

References (3)

Related

Authoritative record: CVE-2021-47493 at cve.org

Vendors: linux

Weaknesses: CWE-362

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-47493 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.