In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Make post-verification instruction rewrites killable<\/p>\n
After do_check() returns, the verifier runs several instruction rewrite
\npasses. Some of them patch or remove one instruction at a time. Each
\noperation moves the remaining instruction and auxiliary-data arrays and
\nadjusts all branch offsets, making the overall work quadratic in the
\nprogram length.<\/p>\n
A privileged loader can submit 131072 unconditional jumps by zero followed
\nby a valid return. Verification finishes quickly, but bpf_opt_remove_nops()
\nthen spends a long time removing each jump separately. Since this
\npost-verification work neither checks for signals nor reschedules, a pending
\nSIGKILL cannot terminate the task until the rewrite finishes.<\/p>\n
Make bpf_patch_insn_data() and verifier_remove_insns() common cancellation
\nand rescheduling points. These helpers run from BPF_PROG_LOAD process
\ncontext, and bpf_patch_insn_data() can already sleep while reallocating
\nauxiliary data.<\/p>\n
Report interrupted constant blinding as -EINTR and propagate it through
\nboth JIT paths, including kernels that permit interpreter fallback.
\nOther blinding failures retain the existing fallback behavior.<\/p>\n
This does not reduce the quadratic cost of the rewrite passes, but it makes
\nthe work preemptible and allows a killed loader to be torn down promptly.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
bpf: Make post-verification instruction rewrites killable<\/p>\n
After do_check() returns, the verifier runs several instruction rewrite<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-41100","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/41100","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=41100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}