In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
smb: client: pin DFS superblock in iterator callback<\/p>\n
tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()
\ntakes its active reference only after iterate_supers_type() has dropped
\ns_umount and its passive reference. Concurrent DFS automount expiry can
\ntherefore free the superblock before cifs_sb_active() uses it.<\/p>\n
A deterministic KASAN test reproduces the race as:<\/p>\n
BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77\/0x80<\/p>\n
The same test passes with this change applied.<\/p>\n
Take the active reference in the callback while iterate_supers_type()
\nstill holds s_umount shared. cifs_put_tcp_super() remains the matching
\nrelease.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
smb: client: pin DFS superblock in iterator callback<\/p>\n
tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()
\ntakes<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-28994","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/28994","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=28994"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28994"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28994"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}