AMD submits Linux update to fix vulnerability that leaks data after Zen 1 architecture divides by zero

News from this site on August 13, Phoronix discovered that AMD has incorporated a new vulnerability fix for the Linux kernel, mainly because the first-generation AMD Zen processor may leak data after dividing by zero.

As of this writing, the Linux 6.4.10 stable kernel and the Linux 6.1.45 / 5.15.126 / 5.10.190 LTS kernel have all fixed this vulnerability.

AMD Linux developer Borislav Petkov wrote a kernel patch to address a bug for Ryzen 1000 series and EPYC 7001 series processors, explaining:

In some cases, An error occurs when dividing an integer by zero, which may leave stale quotient data from previous division operations on Zen1 architectures.

Perform a dummy 0/1 division before returning from the #DE exception handler to avoid any potential sensitive data leakage issues w.

In the code, this issue is simply called "AMD DIV0 Speculation Bug."

Of course, virtual division 0/1 only works on AMD Zen 1 processors. The kernel message added by this patch also states that disabling SMT technology provides "comprehensive" protection against divide-by-zero issues.

In addition to the AMD Zen 1 fixes, various other bugs were fixed in the Linux stable and LTS kernels this week.

Advertising statement: The external jump links contained in the article (including but not limited to hyperlinks, QR codes, passwords, etc.) are used for Convey more information and save selection time. The results are for reference only. All articles on this site contain this statement.

The above is the detailed content of AMD submits Linux update to fix vulnerability that leaks data after Zen 1 architecture divides by zero. For more information, please follow other related articles on the PHP Chinese website!