In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Preserve special fields in recycled rhtab elements<\/p>\n
rhtab_map_update_elem() initializes special fields after obtaining an
\nelement from bpf_mem_cache_alloc(). The allocator can return a fresh,
\nzeroed unit, or recycle one from its RCU-pending lists before the
\nregistered destructor has run.<\/p>\n
A BPF program can retain a map-value pointer after deleting its element
\nand initialize and arm a timer through that pointer. If the deleted unit
\nis recycled, check_and_init_map_value() clears the only pointer to the
\ntimer. Neither a later deletion nor rhtab_mem_dtor() can then cancel it,
\nand the callback can run with its key and value pointing into freed memory.<\/p>\n
Do not reinitialize special fields on insertion. Fresh allocator units are
\nalready zeroed. For recycled units, the special fields are ownership state
\nthat must remain visible to the eventual destructor. copy_map_value()
\nalready skips those fields, matching the non-preallocated hash-map path and
\nthe lifecycle established by commit 275c30bcee66 (“bpf: Don’t reinit map
\nvalue in prealloc_lru_pop”).<\/p>\n
[ kkd: Split out the fix and rewrote the commit log ]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Preserve special fields in recycled rhtab elements<\/p>\n
rhtab_map_update_elem() initializes special fields after obtaining an
\nelem<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29191","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29191","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=29191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}