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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-89607

ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body without bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When encrypted_key_size > 64, decrypt_passphrase_encrypted_session_key() sets decrypted_key_size = encrypted_key_size and performs two out-of-bounds writes: 1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into decrypted_key[64] via scatterlist, overflowing into the parent ecryptfs_auth_tok struct. 2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes into crypt_stat->key[64], corrupting root_iv, keysig_list, and mutexes in ecryptfs_crypt_stat. Only AES-192 (cipher code 0x08) enables this because it sets crypt_stat->key_size = 24 independently of encrypted_key_size, allowing crypto_skcipher_setkey() to succeed while encrypted_key_size exceeds ECRYPTFS_MAX_KEY_BYTES. The PKI decryption path (parse_tag_65_packet) already validates decrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path omits this check. Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also protects the 512-byte encrypted_key[] buffer, so the former 512-byte check is removed as redundant. [tyhicks: Adjust the code comment to refer to macros representing the buffer sizes rather than mentioning the buffer size values since they may change in the future]

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

  • 237fead619984cc48818fe12ee0ceada3f55b012 to < 2cd21340163494d312836c77c9fbfe2530b3d075affected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < e2152d491ae62d96a32ed59778680a242af1fbc6affected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < d2802414081184f79a619ede178aeef3aa989793affected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < 33e050cac841498b5175f0f385eee903fd98863caffected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < ccd13eff0e7356d2aa28b127b577e4e5ad4563f5affected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < 14cb36a500a5a3afbc955dbf69dabc565f1a3b26affected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < a419c9ebfc9a40ee56aaad6dc68bfd67d400817baffected
  • 237fead619984cc48818fe12ee0ceada3f55b012 to < 5babe9c177c364521e3e682b949c5a8c47f4a441affected

Linux Linux

Default version status: affected

  • 2.6.19affected
  • 0 to < 2.6.19unaffected
  • 5.10.270 to ≤ 5.10.*unaffected
  • 5.15.221 to ≤ 5.15.*unaffected
  • 6.1.188 to ≤ 6.1.*unaffected
  • 6.6.157 to ≤ 6.6.*unaffected
  • 6.12.109 to ≤ 6.12.*unaffected
  • 6.18.50 to ≤ 6.18.*unaffected
  • 7.2.4 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References