The Linux kernel adopts a large number of security checks to prevent security-sensitive operations from being executed under unsafe conditions.If a security-sensitive operation is unchecked,a missing-check issue arise...The Linux kernel adopts a large number of security checks to prevent security-sensitive operations from being executed under unsafe conditions.If a security-sensitive operation is unchecked,a missing-check issue arises.Missing check is a class of severe bugs in software programs especially in operating system kernels,which may cause a variety of security issues,such as out-of-bound accesses,permission bypasses,and privilege escalations.Due to the lack of security specifications,how to automatically identify security-sensitive operations and their required security checks in the Linux kernel becomes a challenge for missing-check analysis.In this paper,we present an accurate missing-check analysis method for Linux kernel,which can automatically infer possible security-sensitive operations.Particularly,we first automatically identify all possible security check functions of Linux.Then according to their callsites,a two-direction analysis method is leveraged to identify possible security-sensitive operations.A missing-check bug is reported when the security-sensitive operation is not protected by its corresponding security check.We have implemented our method as a tool,named AMCheX,on top of the LLVM(Low Level Virtual Machine)framework and evaluated it on the Linux kernel.AMCheX reported 12 new missing-check bugs which can cause security issues.Five of them have been confirmed by Linux maintainers.展开更多
基金supported by the National Nature Science Foundation of China under Grant Nos.61802415,62032019 and 62032024.PDF(PC)23。
文摘The Linux kernel adopts a large number of security checks to prevent security-sensitive operations from being executed under unsafe conditions.If a security-sensitive operation is unchecked,a missing-check issue arises.Missing check is a class of severe bugs in software programs especially in operating system kernels,which may cause a variety of security issues,such as out-of-bound accesses,permission bypasses,and privilege escalations.Due to the lack of security specifications,how to automatically identify security-sensitive operations and their required security checks in the Linux kernel becomes a challenge for missing-check analysis.In this paper,we present an accurate missing-check analysis method for Linux kernel,which can automatically infer possible security-sensitive operations.Particularly,we first automatically identify all possible security check functions of Linux.Then according to their callsites,a two-direction analysis method is leveraged to identify possible security-sensitive operations.A missing-check bug is reported when the security-sensitive operation is not protected by its corresponding security check.We have implemented our method as a tool,named AMCheX,on top of the LLVM(Low Level Virtual Machine)framework and evaluated it on the Linux kernel.AMCheX reported 12 new missing-check bugs which can cause security issues.Five of them have been confirmed by Linux maintainers.
