In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: cls_u32: validate offshift to prevent shift-out-of-bounds<\/p>\n
u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char,
\n0-255) into the kernel knode object without bounds validation. When a
\npacket later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates
\n`ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit
\nvalue promoted to a 32-bit int. Any offshift >= 32 is undefined behavior
\nper C11 6.5.7p3, triggerable by an unprivileged user via user\/network
\nnamespaces.<\/p>\n
UBSAN: shift-out-of-bounds in net\/sched\/cls_u32.c:236:43
\nshift exponent 32 is too large for 32-bit type int<\/p>\n
Fix this by rejecting offshift >= 16 during filter creation in
\nu32_change().<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: cls_u32: validate offshift to prevent shift-out-of-bounds<\/p>\n
u32_change() copies the user-provided tc_u32_sel.offshift (un<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-7556","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/7556","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=7556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}