Description: incorrect unprivileged overlayfs permission checking
References:
 https://www.openwall.com/lists/oss-security/2020/10/13/6
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.
Bugs:
upstream: released (5.8-rc1) [48bd024b8a40d73ad6b086de2615738da0c7004f, 56230d956739b9cb1cbde439d76227d77979a04d, 05acefb4872dae89e772729efb194af754c877e8]
4.19-upstream-stable:
4.9-upstream-stable:
sid:
4.19-buster-security:
4.9-stretch-security: