[PATCH RESEND v6 0/3] certs: Prevent spurious errors on repeated blacklisting

[Thomas Weißschuh]

When the blacklist keyring was changed to allow updates from the root
user it gained an ->update() function that disallows all updates.
When the a hash is blacklisted multiple times from the builtin or
firmware-provided blacklist this spams prominent logs during boot:

[    0.890814] blacklist: Problem blacklisting hash (-13)

This affects the firmware of various vendors. Reported have been at least:
* Samsung: https://askubuntu.com/questions/1436856/
* Acer: https://ubuntuforums.org/showthread.php?t=2478840
* MSI: https://forum.archlabslinux.com/t/blacklist-problem-blacklisting-hash-13-errors-on-boot/6674/7
* Micro-Star: https://bbs.archlinux.org/viewtopic.php?id=278860
* Lenovo: https://lore.kernel.org/lkml/c8c65713-5cda-43ad-8018-20f2e32e4432@xxxxxxxx/

Note: In the meantime I lost access to the machine exhibiting the
problematic behavior. If larger changes are required to this series
somebody else would have to validate them or take over the series.

Changelog:

v1: https://lore.kernel.org/all/20221104014704.3469-1-linux@xxxxxxxxxxxxxx/
v1 -> v2:
 * Improve logging message to include the failed hash
 * Add key_create() function without update semantics
 * Use key_create() from mark_raw_hash_blacklisted() and log specific message
   on -EEXIST

v2: https://lore.kernel.org/lkml/20221109025019.1855-1-linux@xxxxxxxxxxxxxx/
v2 -> v3:
 * Clarify commit titles and messages
 * Drop the change to BLACKLIST_KEY_PERM from patch 3, as it was an artifact
   of some obsolete version of the patch and not needed

v3: https://lore.kernel.org/lkml/20221118040343.2958-1-linux@xxxxxxxxxxxxxx/
v3 -> v4:
 * Drop Fixes-tag from first patch
 * Flesh out commit descriptions and messages

v4: https://lore.kernel.org/r/20221212-keys-blacklist-v4-0-00afeb3137fb@xxxxxxxxxxxxxx
v4 -> v5:
 * Reduce lines needed by function calls in key.c
 * Add Reviewed-by from Jarkko

v5: https://lore.kernel.org/r/20221212-keys-blacklist-v5-0-52e9eb5a8827@xxxxxxxxxxxxxx
v5 -> v6:
 * Correct Jarkkos email in Reviewed-by tags
 * Resend to hopefully reach @kernel.org recipients

Thomas Weißschuh (3):
  certs: log hash value on blacklist error
  KEYS: Add key_create()
  certs: don't try to update blacklist keys

 certs/blacklist.c   |  21 ++++---
 include/linux/key.h |   8 +++
 security/keys/key.c | 149 +++++++++++++++++++++++++++++++++-----------
 3 files changed, 132 insertions(+), 46 deletions(-)

--
2.38.1

To: David Howells <dhowells@xxxxxxxxxx>
To: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
To: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
To: Paul Moore <paul@xxxxxxxxxxxxxx>
To: James Morris <jmorris@xxxxxxxxx>
To: "Serge E. Hallyn" <serge@xxxxxxxxxx>
To: "Mickaël Salaün" <mic@xxxxxxxxxxx>
Cc: keyrings@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-security-module@xxxxxxxxxxxxxxx
Cc: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Cc: Mark Pearson <markpearson@xxxxxxxxxx>

---
Thomas Weißschuh (3):
      certs: make blacklisted hash available in klog
      KEYS: Add new function key_create()
      certs: don't try to update blacklist keys

 certs/blacklist.c   |  21 ++++----
 include/linux/key.h |   8 +++
 security/keys/key.c | 137 ++++++++++++++++++++++++++++++++++++++--------------
 3 files changed, 120 insertions(+), 46 deletions(-)
---
base-commit: 512dee0c00ad9e9c7ae9f11fc6743702ea40caff
change-id: 20221212-keys-blacklist-2c79a64667c9

Best regards,
-- 
Thomas Weißschuh <linux@xxxxxxxxxxxxxx>