[SRU][K/L/Unstable][PATCH 0/1] UBUNTU: SAUCE: overlayfs: handle idmapped mounts in ovl_do_(set|remove)xattr (LP: 2009065)

[Alexander Mikhalitsyn]

BugLink: http://bugs.launchpad.net/bugs/2009065

SRU Justification:

[Impact]

Unprivileged LXC containers users with idmapped root (Ubuntu kernels >= 5.19) getting
all overlayfs mounts inside mounted as R/O.

Impacted Ubuntu versions J/K/L. Jammy is affected only with hwe-5.19.

[Fix]

813fa2cd9e259dacd8f9086226287dc167c8c0c5 "UBUNTU: SAUCE: overlayfs: handle idmapped mounts in
 ovl_do_(set|remove)xattr"

[Test Plan]

Reproducer:
$ cd /idmapped/mount/path
$ mkdir {work,upper,lower,ovl}
$ mount -t overlay overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl
$ touch ovl/test
touch: cannot touch 'ovl/test': Read-only file system

[Where problems could occur]

The regression can be considered as low, because we just making things to work the same way as in upstream.

[Other Info]

We need to apply this patch to Jammy/hwe-5.19 tree too. The same patch can be applied to kinetic/master, lunar/master, unstable (6.2) tree.

Alexander Mikhalitsyn (1):
  UBUNTU: SAUCE: overlayfs: handle idmapped mounts in
    ovl_do_(set|remove)xattr

 fs/overlayfs/overlayfs.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.34.1