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The Cyrix coma bug is a design flaw in Cyrix 6x86, 6x86L, and early 6x86MX processors that allows a non-privileged program to hang the computer. ==Discovery== According to Andrew Balsa, around the time of the discovery of the F00F bug on Intel Pentium, Serguei Shtyliov from Moscow found a flaw in a Cyrix processor while developing an IDE disk driver in assembly language. Alexandr Konosevich, from Omsk, further researched the bug and coauthored an article with Uwe Post in the German technology magazine ''c't'', calling it the "hidden CLI bug" (CLI is the instruction that disables interrupts in the x86 architecture). Balsa, as a member on the Linux-kernel mailing list, confirmed that the following C program could be compiled and run by an unprivileged user: unsigned char c() = ; int main() Execution of this program renders the processor completely useless, as it enters an infinite loop that cannot be interrupted. This presents a security flaw because any user with access to a Cyrix system with this bug could prevent other users from using the system. Exploitation of this flaw would therefore be a denial-of-service attack. It is similar to execution of a Halt and Catch Fire instruction, although the coma bug is not any one particular instruction. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyrix coma bug」の詳細全文を読む スポンサード リンク
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