CVE-2019-15793

Description

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.

Weakness classification

• security@ubuntu.com: CWE-538
• nvd@nist.gov: CWE-276

Primary references

• security@ubuntu.com — Mailing List, Patch, Third Party Advisory
• security@ubuntu.com — Third Party Advisory
• security@ubuntu.com — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Patch, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory