CVE-ID

CVE-2017-1000255

• Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings
Description
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 kernel memory has been over written. This flaw was introduced in commit: "5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
Assigning CNA
Distributed Weakness Filing Project
Date Entry Created
20171006 Disclaimer: The entry creation date may reflect when the CVE-ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20171006)
Votes (Legacy)
Comments (Legacy)
Proposed (Legacy)
N/A
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