In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
fscrypt: Add missing superblock check in find_or_insert_direct_key()<\/p>\n
The legacy ‘fscrypt_direct_keys’ table caches master keys that are used
\nby v1 encryption policies that have FSCRYPT_POLICY_FLAG_DIRECT_KEY.
\nIt’s just a global table for all filesystems (since the keys can be
\nprovided by the legacy process-subscribed keyrings mechanism, which
\nmakes it difficult to reuse super_block::s_master_keys).<\/p>\n
The entries in it (‘struct fscrypt_direct_key’) do contain a super_block
\npointer, though, for passing to fscrypt_destroy_inline_crypt_key() when
\nthe last inode that references the key is evicted.<\/p>\n
However, when finding the fscrypt_direct_key for an inode, we weren’t
\nactually comparing the super_block pointer. As a result, inodes with
\ndifferent super_blocks could point to the same fscrypt_direct_key. That
\ncould extend the lifetime of a fscrypt_direct_key beyond the
\nsuper_block it points to, causing a use-after-free later.<\/p>\n
Fix this by creating distinct fscrypt_direct_key structs for distinct
\nsuper_block structs.<\/p>\n
Note that this problem doesn’t exist in the v2 policy equivalent
\n(“per-mode keys”), since the data structures there are per super_block.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
fscrypt: Add missing superblock check in find_or_insert_direct_key()<\/p>\n
The legacy ‘fscrypt_direct_keys’ table caches master keys tha<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5354","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5354","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=5354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}