In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
wifi: cfg80211: validate rx\/tx MLME callback frame lengths before access<\/p>\n
cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() call tracepoints
\nbefore rejecting frames shorter than the frame-control field. After
\nthat, they only require len >= 2 before dispatching into subtype
\nhandlers that assume their fixed fields are present.<\/p>\n
The frames that trip this are not shorter than 2 bytes; they are short
\nrelative to their subtype. mwifiex is a concrete in-tree example on the
\nlength side: mwifiex_process_mgmt_packet() only requires a 4-address
\nieee80211_hdr plus the 2-byte firmware length prefix before handing the
\nframe to cfg80211_rx_mlme_mgmt(). After stripping the length prefix and
\nremoving addr4, pkt_len can be exactly 24: a bare 3-address management
\nheader with no reason-code body. The existing WARN_ON(len < 2) does not
\nfire on such a frame, and cfg80211_process_deauth() then reads
\nu.deauth.reason_code as a two-byte access starting at offset 24,
\nimmediately past the 24-byte buffer.<\/p>\n
Add a frame-control length gate, then validate each subtype's minimum
\nframe size in an if\/else-if chain that mirrors the dispatch logic. Trace
\nonly after the frame is known to be well-formed.<\/p>\n
Side effects of this change:
\n – The WARN_ON(len = 2).
\n The len >= 2 check is kept as the guard before dereferencing
\n frame_control, but without the warning: these are exported callbacks
\n and a malformed frame from a driver should be dropped silently rather
\n than backtraced.
\n – cfg80211_tx_mlme_mgmt() previously routed every non-deauth subtype
\n through disassociation handling; it now silently ignores unrecognised
\n subtypes.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
wifi: cfg80211: validate rx\/tx MLME callback frame lengths before access<\/p>\n
cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() call <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-28620","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/28620","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=28620"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28620"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28620"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}