{"id":25984,"date":"2026-09-18T04:32:11","date_gmt":"2026-09-17T20:32:11","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-93127"},"modified":"2026-09-18T04:32:11","modified_gmt":"2026-09-17T20:32:11","slug":"cve-2026-93127","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-93127","title":{"rendered":"CVE-2026-93127 &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Drop scalar id o"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>bpf: Drop scalar id on sign-extending narrowing stack fills<\/p>\n<p>When a spilled scalar is filled back with a sign-extending narrowing load<br \/>\n(BPF_MEMSX), check_stack_read_fixed_off() copies the spilled register<br \/>\nincluding its scalar id, but coerce_reg_to_size_sx() then sign-extends the<br \/>\nfilled register&#8217;s value. If the same slot is also filled with a plain<br \/>\nzero-extending load (BPF_MEM), both destination registers share the id yet<br \/>\nhold different values. A later &#8216;if  == const&#8217; then refines the<br \/>\nsign-extended register through sync_linked_regs() to a value it does not<br \/>\nhave at runtime (e.g. the verifier believes 0x80000000 while the register<br \/>\nis 0xffffffff80000000), which can be turned into an out-of-bounds access.<\/p>\n<p>Drop the shared scalar id at the sign-extension site in check_mem_access()<br \/>\nwhen sign extension actually changes the value, mirroring the BPF_MOVSX<br \/>\nhandling in check_alu_op() (no_sext = reg_umax &lt; 2^(size*8-1)).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>bpf: Drop scalar id on sign-extending narrowing stack fills<\/p>\n<p>When a spilled scalar is filled back with a sign-extending narrowing l<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-25984","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/25984","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=25984"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25984"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25984"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}