In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
netfs: Fix missing barriers when accessing stream->subrequests locklessly<\/p>\n
The list of subrequests attached to stream->subrequests is accessed without
\nlocks by netfs_collect_read_results() and netfs_collect_write_results(),
\nand then they access subreq->flags without taking a barrier after getting
\nthe subreq pointer from the list. Relatedly, the functions that build the
\nlist don’t use any sort of write barrier when constructing the list to make
\nsure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if
\nno lock is taken.<\/p>\n
Fix this by:<\/p>\n
(1) Add a new list_add_tail_release() function that uses a release barrier
\n to set the pointer to the new member of the list.<\/p>\n
(2) Add a new list_first_entry_or_null_acquire() function that uses an
\n acquire barrier to read the pointer to the first member in a list (or
\n return NULL).<\/p>\n
(3) Use list_add_tail_release() when adding a subreq to ->subrequests.<\/p>\n
(4) Use list_first_entry_or_null_acquire() when initially accessing the
\n front of the list (when an item is removed, the pointer to the new
\n front iterm is obtained under the same lock).<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
netfs: Fix missing barriers when accessing stream->subrequests locklessly<\/p>\n
The list of subrequests attached to stream->subrequests <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-15049","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/15049","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=15049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}