CVE-2021-47239: net: usb: fix possible use-after-free in smsc75xx_bind

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• linux linux kernel4.4.271 and later · before 4.4.274
• linux linux kernel4.9.271 and later · before 4.9.274
• linux linux kernel4.14.235 and later · before 4.14.238
• linux linux kernel4.19.193 and later · before 4.19.196
• linux linux kernel5.4.124 and later · before 5.4.128
• linux linux kernel5.10.42 and later · before 5.10.46
• linux linux kernel5.12.9 and later · before 5.12.13

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

  • 200dbfcad8011e50c3cec269ed7b980836eeb1fa and later · before 7cc8b2e05fcea6edd022d26e82091d781af8fd9baffected · git
  • 22c840596af0c09068b6cf948616e6496e59e07f and later · before 64160d1741a3de5204d1a822e058e0b4cc526504affected · git
  • 9e6b8c1ff9d997e1fa16cbd2d60739adf6dc1bbc and later · before c4e3be2e7742863e454ce31faf8fd0109c00050baffected · git
  • 9e6a3eccb28779710cbbafc4f4258d92509c6d07 and later · before 2fc8300c9cfa5167fcb5b1a2a07db6f53e82f59baffected · git
  • b95fb96e6339e34694dd578fb6bde3575b01af17 and later · before 4252bf6c2b245f47011098113d405ffad6ad5d5baffected · git
  • 635ac38b36255d3cfb8312cf7c471334f4d537e0 and later · before 570a52cf3e01d19f7fd1a251dfc52b0cd86c13cbaffected · git
  • 70c886ac93f87ae7214a0c69151a28a8075dd95b and later · before 14616c372a7be01a2fb8c56c9d8debd232b9e43daffected · git
  • 46a8b29c6306d8bbfd92b614ef65a47c900d8e70 and later · before 56b786d86694e079d8aad9b314e015cd4ac02a3daffected · git
  • 4.4.271 and later · before 4.4.274affected · semver
  • 4.9.271 and later · before 4.9.274affected · 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-2021-47237May 21, 2024 · net: hamradio: fix memory leak in mkiss_close
  22Monitor
• ← EarlierCVE-2021-47238May 21, 2024 · net: ipv4: fix memory leak in ip_mc_add1_src
  22Monitor
• Later →CVE-2021-47240May 21, 2024 · net: qrtr: fix OOB Read in qrtr_endpoint_post
  28Monitor

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.