In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
dma-buf\/dma-fence: fix checking signaling bit for timeline and driver name v3<\/p>\n
The patch “dma-buf: dma-fence: Fix potential NULL pointer dereference”
\nchanged the check to test for the ops pointer instead of the signaled
\nbit to avoid a potential NULL dereference when the ops pointer has been
\ncleared.<\/p>\n
The problem is now that the ops pointer is cleared only when neither the
\nrelease nor the wait callback is implemented and this isn’t true for a lot
\nof dma_fence implementations yet. So those implementations lost the RCU
\nprotection after signaling of the returned string resulting in potential
\nuse after free.<\/p>\n
Add the signaling check additional to the ops pointer check so that we
\nhave both the protection against NULL dereference as well as the RCU
\nprotection after signaling for the returned string.<\/p>\n
v2: improve comments to note RCU protection and explain why we check
\n both signaling state and ops pointer
\nv3: some comment improvements suggested by Philip<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
dma-buf\/dma-fence: fix checking signaling bit for timeline and driver name v3<\/p>\n
The patch “dma-buf: dma-fence: Fix potential NULL po<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-33312","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/33312","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=33312"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=33312"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=33312"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}