cve/2020/CVE-2020-29374.md

CVE-2020-29374

Description

An issue was discovered in the Linux kernel before 5.7.3, related to mm/gup.c and mm/huge_memory.c. The get_user_pages (aka gup) implementation, when used for a copy-on-write page, does not properly consider the semantics of read operations and therefore can grant unintended write access, aka CID-17839856fd58.

POC

Reference

• http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
• http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.3
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.3
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=17839856fd588f4ab6b789f482ed3ffd7c403e1f
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=17839856fd588f4ab6b789f482ed3ffd7c403e1f

Github

• https://github.com/Moonshieldgru/Moonshieldgru
• https://github.com/defgsus/good-github