In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ceph: bound MDSCapAuth path and fs_name decode in handle_session()<\/p>\n
handle_session() decodes the MDSCapAuth records carried by a
\nCEPH_SESSION_OPEN message (msg_version >= 6). For each record the
\nmatch.path and match.fs_name byte strings are read by first decoding a
\n32-bit length and then copying that many bytes with the bare
\nceph_decode_copy(). Unlike the surrounding fields, which all use the
\n_safe decode variants, these two copies are not preceded by a
\nceph_decode_need() bounds check, and the enclosing MDSCapAuth and
\nMDSCapMatch struct_len fields are skipped rather than enforced as an
\nupper bound. A length larger than the bytes remaining in the message
\nfront makes ceph_decode_copy() read past the end of the front buffer.<\/p>\n
The message front is a dedicated allocation (ceph_msg_new2() ->
\nkvmalloc), so the over-read runs off that object. A malicious or
\ncompromised MDS can trigger this with the first post-connect message on
\nmount, with no client-side user interaction; under KASAN it is reported
\nas a slab-out-of-bounds read in handle_session().<\/p>\n
Impact: a malicious MDS can force the kernel client to read up to 4 GiB
\npast the message front allocation during session setup, crashing the
\nclient (out-of-bounds read).<\/p>\n
Switch both copies to ceph_decode_copy_safe(), which performs the
\nceph_decode_need() bounds check before the copy and branches to the
\nexisting bad label, matching the rest of the decoder and the error path
\nthat frees the partially decoded cap_auths array.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ceph: bound MDSCapAuth path and fs_name decode in handle_session()<\/p>\n
handle_session() decodes the MDSCapAuth records carried by a
\nCE<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21573","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21573","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=21573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}