In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations<\/p>\n
When fuzzing the nvme target code, I tripped a kernel warning in
\nnvmet_tcp_map_data() because the length passed into the allocator is
\ncontrolled by the remote initiator.<\/p>\n
A remote initiator that sends a command with an SGL claiming a huge
\nnumber, can create a scatterlist and iovec allocation of over 1 million
\nentries, which causes the backing kmalloc call to exceed MAX_PAGE_ORDER
\nand then the page allocator will trip on a WARN_ON_ONCE_GFP() message:<\/p>\n
WARNING: mm\/page_alloc.c:5280 __alloc_frozen_pages_noprof
\n Workqueue: nvmet_tcp_wq nvmet_tcp_io_work
\n …
\n sgl_alloc_order
\n nvmet_tcp_map_data
\n nvmet_tcp_try_recv_pdu<\/p>\n
As it’s never good to trip a kernel warning remotely due to many systems
\nhaving panic-on-warn enabled, let’s silence it by just add GFP_NOWARN to
\nthe allocation flags.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations<\/p>\n
When fuzzing the nvme target code, I tripped a kernel warn<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-17292","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/17292","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=17292"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17292"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17292"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}