In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: mcast: Fix potential UAF in MLD delayed work<\/p>\n
A race condition exists between device teardown and incoming MLD query
\nprocessing, leading to a Use-After-Free in the MLD delayed work.<\/p>\n
During device destruction, the primary reference to inet6_dev is dropped,
\nwhich can drop its refcount to 0. The actual freeing of inet6_dev memory
\nis deferred via RCU.<\/p>\n
Concurrently, the packet receive path runs under RCU read lock and obtains
\nthe inet6_dev pointer. Because the memory is RCU-protected, CPU-0 can
\nsafely dereference inet6_dev even if its refcount has hit 0.<\/p>\n
However, if CPU-0 calls igmp6_event_query() and schedules delayed work, it
\nattempts to acquire a reference using in6_dev_hold(). This increments the
\nrefcount from 0 to 1, triggering a “refcount_t: addition on 0” warning.
\nSince the inet6_dev memory is still scheduled to be freed after the RCU
\ngrace period, the device is freed while the work is still scheduled.
\nWhen the work runs, it accesses the freed memory, causing a kernel panic.<\/p>\n
Fix this by using refcount_inc_not_zero() (via a new helper
\nin6_dev_hold_safe()) to prevent acquiring a reference if the device is
\nalready being destroyed. If the refcount is 0, we do not schedule the work.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: mcast: Fix potential UAF in MLD delayed work<\/p>\n
A race condition exists between device teardown and incoming MLD query
\nprocessi<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-6949","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/6949","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=6949"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6949"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6949"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}