CVE-2020-16120

incorrect unprivileged overlayfs permission checking

References

Notes

 carnil> Additionally to the three fixing commits
 carnil> 130fdbc3d1f9966dd4230709c30f3768bccd3065 ("ovl: pass correct
 carnil> flags for opening real directory") and
 carnil> 292f902a40c11f043a5ca1305a114da0e523eaa3 ("ovl: call secutiry
 carnil> hook in ovl_real_ioctl()") might be wanted (see oss-security
 carnil> post).
 carnil> Only exploitable when unprivileged user namespaces are enabled.
 bwh> I think it's only exploitable when unprivileged user namespace
 bwh> are enabled, *and* mounting of overlayfs is permitted in all
 bwh> user namespaces.  This is not possible in the upstream or stable
 bwh> kernels, or in a default Debian configuration, but we do provide
 bwh> run-time configuration knobs to enable these.

Bugs

Status

Branch Status
4.19-buster-security needed
4.19-upstream-stable N/A "Vulnerable configuration not possible"
5.10-bullseye-security N/A "Fixed before branching point"
5.10-upstream-stable N/A "Fixed before branch point"
6.1-bookworm-security N/A "Fixed before branch point"
6.1-upstream-stable N/A "Fixed before branch point"
6.6-upstream-stable unknown
6.8-upstream-stable unknown
sid released (5.8.7-1)
upstream released (5.8-rc1) [48bd024b8a40d73ad6b086de2615738da0c7004f, 56230d956739b9cb1cbde439d76227d77979a04d, 05acefb4872dae89e772729efb194af754c877e8]