In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet<\/p>\n
parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body
\nwithout bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When
\nencrypted_key_size > 64, decrypt_passphrase_encrypted_session_key()
\nsets decrypted_key_size = encrypted_key_size and performs two
\nout-of-bounds writes:<\/p>\n
1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into
\n decrypted_key[64] via scatterlist, overflowing into the parent
\n ecryptfs_auth_tok struct.
\n2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes
\n into crypt_stat->key[64], corrupting root_iv, keysig_list, and
\n mutexes in ecryptfs_crypt_stat.<\/p>\n
Only AES-192 (cipher code 0x08) enables this because it sets
\ncrypt_stat->key_size = 24 independently of encrypted_key_size,
\nallowing crypto_skcipher_setkey() to succeed while encrypted_key_size
\nexceeds ECRYPTFS_MAX_KEY_BYTES.<\/p>\n
The PKI decryption path (parse_tag_65_packet) already validates
\ndecrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path
\nomits this check.<\/p>\n
Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather
\nthan ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also
\nprotects the 512-byte encrypted_key[] buffer, so the former 512-byte
\ncheck is removed as redundant.<\/p>\n
[tyhicks: Adjust the code comment to refer to macros representing the
\n buffer sizes rather than mentioning the buffer size values since they
\n may change in the future]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet<\/p>\n
parse_tag_3_packet() set encrypted_key_size from the Tag 3 pac<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21529","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21529","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21529"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21529"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21529"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}