linux/security
David Gstir 0e28bf61a5 KEYS: trusted: dcp: fix leak of blob encryption key
Trusted keys unseal the key blob on load, but keep the sealed payload in
the blob field so that every subsequent read (export) will simply
convert this field to hex and send it to userspace.

With DCP-based trusted keys, we decrypt the blob encryption key (BEK)
in the Kernel due hardware limitations and then decrypt the blob payload.
BEK decryption is done in-place which means that the trusted key blob
field is modified and it consequently holds the BEK in plain text.
Every subsequent read of that key thus send the plain text BEK instead
of the encrypted BEK to userspace.

This issue only occurs when importing a trusted DCP-based key and
then exporting it again. This should rarely happen as the common use cases
are to either create a new trusted key and export it, or import a key
blob and then just use it without exporting it again.

Fix this by performing BEK decryption and encryption in a dedicated
buffer. Further always wipe the plain text BEK buffer to prevent leaking
the key via uninitialized memory.

Cc: stable@vger.kernel.org # v6.10+
Fixes: 2e8a0f40a3 ("KEYS: trusted: Introduce NXP DCP-backed trusted keys")
Signed-off-by: David Gstir <david@sigma-star.at>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2024-08-15 22:01:14 +03:00
..
apparmor apparmor-pr-2024-07-24 PR 2024-07-25 2024-07-27 13:28:39 -07:00
bpf lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
integrity This update includes the following changes: 2024-07-19 08:52:58 -07:00
keys KEYS: trusted: dcp: fix leak of blob encryption key 2024-08-15 22:01:14 +03:00
landlock Landlock security fix for v6.11-rc1 2024-07-27 13:16:53 -07:00
loadpin hardening fixes for v6.10-rc1 2024-05-24 08:33:44 -07:00
lockdown LSM: Identify modules by more than name 2023-11-12 22:54:42 -05:00
safesetid lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
selinux selinux: revert our use of vma_is_initial_heap() 2024-08-08 16:22:47 -04:00
smack Two fixes for Smack networking by Konstantin Andreev. 2024-07-16 14:56:13 -07:00
tomoyo tomoyo: update project links 2024-06-03 22:43:11 +09:00
yama sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
commoncap.c lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
device_cgroup.c device_cgroup: Fix kernel-doc warnings in device_cgroup 2023-06-21 09:30:49 -04:00
inode.c security: convert to new timestamp accessors 2023-10-18 14:08:31 +02:00
Kconfig fortify: drop Clang version check for 12.0.1 or newer 2024-02-22 15:38:54 -08:00
Kconfig.hardening Revert "mm: init_mlocked_on_free_v3" 2024-06-15 10:43:05 -07:00
lsm_audit.c
lsm_syscalls.c lsm: use 32-bit compatible data types in LSM syscalls 2024-03-14 11:31:26 -04:00
Makefile LSM: syscalls for current process attributes 2023-11-12 22:54:42 -05:00
min_addr.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
security.c lsm/stable-6.11 PR 20240715 2024-07-16 14:50:44 -07:00