[SRU][Xenial][Bionic][PATCH 0/1] getxattr: use correct xattr length

[Joseph Salisbury]

BugLink: https://bugs.launchpad.net/bugs/1789746

== SRU Justification ==
When running in a container with a user namespace, if you call getxattr
with name = "system.posix_acl_access" and size % 8 != 4, then getxattr
silently skips the user namespace fixup that it normally does resulting in
un-fixed-up data being returned.

This is caused by posix_acl_fix_xattr_to_user() being passed the total
buffer size and not the actual size of the xattr as returned by
vfs_getxattr().

This commit has already been applied to Cosmic master-next.

== Fix ==
82c9a927bc5d ("getxattr: use correct xattr length")

== Regression Potential ==
Low.  One liner that passes the actual length of the xattr as returned by
vfs_getxattr() down.

== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.


Christian Brauner (1):
  getxattr: use correct xattr length

 fs/xattr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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2.7.4