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CVE PROGRAM SOURCE RECORD9.1 Critical

CVE-2026-64551

sctp: validate STALE_COOKIE cause length before reading staleness

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: validate STALE_COOKIE cause length before reading staleness When an ERROR chunk with a STALE_COOKIE cause is received in the COOKIE_ECHOED state, sctp_sf_do_5_2_6_stale() reads the 4-byte Measure of Staleness that follows the cause header: err = (struct sctp_errhdr *)(chunk->skb->data); stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err))); err is the first cause in the chunk, not the STALE_COOKIE cause that caused the dispatch, and nothing guarantees the staleness field is present. sctp_walk_errors() only requires a cause to be as long as the 4-byte header, so for a STALE_COOKIE cause of length 4 the read runs past the cause, and for a minimal ERROR chunk past skb->tail. The value is echoed to the peer in the Cookie Preservative of the reply INIT, leaking uninitialized memory. sctp_sf_cookie_echoed_err() already walks to the STALE_COOKIE cause, so check its length there and pass it to sctp_sf_do_5_2_6_stale(), which reads that cause instead of the first one. A STALE_COOKIE cause too short to hold the staleness field is discarded. The read is reachable by any peer that can drive an association into COOKIE_ECHOED, including an unprivileged process using a raw SCTP socket in a user and network namespace.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 6022da37786701df1fc5dd946a6dcba59d5473b1affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 861f884f5471632c731cbbd612a1c072e391a624affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 588706ebaf8cdb4a4161602949eba365514b1db1affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < a257b41ddfe9e327b26581ad2777f04b23ac73f5affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 08a8f2d13f703924316e9aeac863a88ef50990c7affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < ebe0a55d954fa8da383b6192edb8f763dcb002d5affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 1cd23ca80784223fa2204e16203f754da4e821f8affected

Linux Linux

Default version status: affected

  • 2.6.12affected
  • 0 to < 2.6.12unaffected
  • 5.10.261 to ≤ 5.10.*unaffected
  • 5.15.212 to ≤ 5.15.*unaffected
  • 6.1.178 to ≤ 6.1.*unaffected
  • 6.6.145 to ≤ 6.6.*unaffected
  • 6.12.97 to ≤ 6.12.*unaffected
  • 6.18.40 to ≤ 6.18.*unaffected
  • 7.1.5 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References