linux/security
Roberto Sassu e3ccfe1ad7 evm: Introduce evm_revalidate_status()
When EVM_ALLOW_METADATA_WRITES is set, EVM allows any operation on
metadata. Its main purpose is to allow users to freely set metadata when it
is protected by a portable signature, until an HMAC key is loaded.

However, callers of evm_verifyxattr() are not notified about metadata
changes and continue to rely on the last status returned by the function.
For example IMA, since it caches the appraisal result, will not call again
evm_verifyxattr() until the appraisal flags are cleared, and will grant
access to the file even if there was a metadata operation that made the
portable signature invalid.

This patch introduces evm_revalidate_status(), which callers of
evm_verifyxattr() can use in their xattr hooks to determine whether
re-validation is necessary and to do the proper actions. IMA calls it in
its xattr hooks to reset the appraisal flags, so that the EVM status is
re-evaluated after a metadata operation.

Lastly, this patch also adds a call to evm_reset_status() in
evm_inode_post_setattr() to invalidate the cached EVM status after a
setattr operation.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-05-21 12:47:12 -04:00
..
apparmor Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-02 09:14:01 -07:00
bpf bpf: Implement task local storage 2020-11-06 08:08:37 -08:00
integrity evm: Introduce evm_revalidate_status() 2021-05-21 12:47:12 -04:00
keys trusted-keys: match tpm_get_ops on all return paths 2021-05-12 22:36:37 +03:00
landlock landlock: Enable user space to infer supported features 2021-04-22 12:22:11 -07:00
loadpin LSM: Add "contents" flag to kernel_read_file hook 2020-10-05 13:37:03 +02:00
lockdown Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2020-06-02 17:36:24 -07:00
safesetid LSM: SafeSetID: Fix code specification by scripts/checkpatch.pl 2021-04-26 16:36:50 -07:00
selinux Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
smack Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
tomoyo tomoyo: don't special case PF_IO_WORKER for PF_KTHREAD 2021-03-28 13:11:29 +09:00
yama task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
commoncap.c Miscellaneous minor fixes for v5.13. 2021-04-27 19:32:55 -07:00
device_cgroup.c device_cgroup: Fix RCU list debugging warning 2020-08-20 11:25:03 -07:00
inode.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
Kconfig landlock: Set up the security framework and manage credentials 2021-04-22 12:22:10 -07:00
Kconfig.hardening kasan: remove redundant config option 2021-04-16 16:10:36 -07:00
lsm_audit.c make dump_common_audit_data() safe to be called from RCU pathwalk 2021-01-16 15:12:08 -05:00
Makefile landlock: Add object management 2021-04-22 12:22:10 -07:00
min_addr.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
security.c Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00