[PATCH for 4.19.y 0/3] Backport Smack fixes for 4.19.y

[Munehisa Kamata <kamatam@amazon.com>]

This series backports the following fixes for Smack problems with overlayfs
to 4.19.y.

2c085f3a8f23 smack: Record transmuting in smk_transmuted
3a3d8fce31a4 smack: Retrieve transmuting information in smack_inode_getsecurity() 
387ef964460f Smack:- Use overlay inode label in smack_inode_copy_up()

This slightly modifies the original commits, because the commits rely on
some helper functions introduced after v4.19 by different commits that
touch more code than just Smack, require even more prerequisite commits and
also need some adjustments for 4.19.y.  Instead, this series makes minor
modifications for only the overlayfs-related fixes to not use the helper
functions rather than backporting everything.

For reference, the upstream commits listed below introduced the helper
functions.  Though, this is not a complete list for their dependencies.

ecd5f82e05dd LSM: Infrastructure management of the ipc security blob
019bcca4626a Smack: Abstract use of ipc security blobs
afb1cbe37440 LSM: Infrastructure management of the inode security
fb4021b6fb58 Smack: Abstract use of inode security blob
33bf60cabcc7 LSM: Infrastructure management of the file security
f28952ac9008 Smack: Abstract use of file security blob
bbd3662a8348 Infrastructure management of the cred security blob
b17103a8b8ae Smack: Abstract use of cred security blob

Roberto Sassu (2):
  smack: Retrieve transmuting information in smack_inode_getsecurity()
  smack: Record transmuting in smk_transmuted

Vishal Goel (1):
  Smack:- Use overlay inode label in smack_inode_copy_up()

 security/smack/smack.h     |  1 +
 security/smack/smack_lsm.c | 65 ++++++++++++++++++++++++++++----------
 2 files changed, 49 insertions(+), 17 deletions(-)

-- 
2.34.1