CVE-2021-47361: mcb: fix error handling in mcb_alloc_bus()

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

• Linux Linux

  • 4.7affected
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 8a558261fa57a6deefb0925ab1829f698b194aeaaffected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 115b07d9f47e3996430b8f2007edd9768e1f807faffected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 66f74ba9be9daf9c47fface6af3677f602774f6baffected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 7751f609eadf36b1f53712bae430019c53a16eb0affected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 91e4ad05bf18322b5921d1a6c9b603f6eb1694f0affected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 9fc198f415dee070a1de957bb5bf5921d8df3499affected · git
  • 18d28819809909c3f24bb72183a901c5e332a63d and later · before 25a1433216489de4abc889910f744e952cb6dbaeaffected · git
  • before 4.7not affected · semver
  • 4.9.285 and later · up to and including 4.9.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
  90Now
• CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
  89Now
• CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
  85Now

Published before and after this one in the same product

• ← EarlierCVE-2021-47359May 21, 2024 · cifs: Fix soft lockup during fsstress
  22Monitor
• ← EarlierCVE-2021-47360May 21, 2024 · binder: make sure fd closes complete
  22Monitor
• Later →CVE-2021-47362May 21, 2024 · drm/amd/pm: Update intermediate power state for SI
  22Monitor

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1free(dev->buf);2/* ... another thread is still running ... */3process(dev->buf);

1lock(&dev->lock);2free(dev->buf);3dev->buf = NULL;4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.