In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
smb: client: fix use-after-free of iface in cifs_try_adding_channels()<\/p>\n
cifs_try_adding_channels() iterates ses->iface_list with
\nlist_for_each_entry_safe_from(), which captures the next entry
\n(niface) under iface_lock. The loop body then drops iface_lock for
\nthe whole duration of cifs_ses_add_channel().<\/p>\n
A concurrent interface refresh (SMB3_request_interfaces() ->
\nparse_server_interfaces()) marks all ifaces inactive and removes and
\nfrees any that are not re-advertised via list_del() + kref_put(),
\nwhere release_iface() is a bare kfree(). Since niface typically has
\nno channel holding a reference, the list reference is its last and it
\ncan be freed inside the unlocked window. On continue, the iterator
\nadvance step then dereferences niface->iface_head.next, and the loop
\nbody reads iface->rdma_capable\/is_active, both on freed memory.<\/p>\n
Fix this by never keeping an unreferenced list pointer across the
\nunlocked window. Each channel attempt now re-scans the list from the
\nhead under iface_lock, takes a kref on the selected candidate, and
\npasses only that referenced candidate to cifs_ses_add_channel().
\nweight_fulfilled still tracks selection progress, so restarting the
\nscan preserves the original weighted distribution and the
\nweight_fulfilled-before-kref_put ordering on the failure path.<\/p>\n
Add a per-pass attempts cap so a flapping interface refresh cannot
\nkeep the inner loop spinning within a single tries increment.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
smb: client: fix use-after-free of iface in cifs_try_adding_channels()<\/p>\n
cifs_try_adding_channels() iterates ses->iface_list with
\nli<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-33242","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/33242","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=33242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33242"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}