CVSS: 6.5EPSS: 0%CPEs: 5EXPL: 1CVE-2020-8834 – Linux kernel KVM Power8 conflicting use of HSTATE_HOST_R1
https://notcve.org/view.php?id=CVE-2020-8834
07 Apr 2020 — KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore}_tm, leading to a stack corruption. Because of this, an attacker with the ability run code in kernel space of a guest VM can cause the host kernel to panic. There were two commits that, according to the reporter, introduced the vulnerability: f024ee098476 ("KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures") 87a11bb6a7f7 ("KVM: PPC:... • http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html • CWE-121: Stack-based Buffer Overflow CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') CWE-368: Context Switching Race Condition •
CVSS: 6.6EPSS: 0%CPEs: 3EXPL: 0CVE-2017-1000255 – kernel: Arbitrary stack overwrite causing oops via crafted signal frame
https://notcve.org/view.php?id=CVE-2017-1000255
11 Oct 2017 — On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after ... • http://www.securityfocus.com/bid/101264 • CWE-787: Out-of-bounds Write •