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| author | Matthew Garrett <matthewgarrett@google.com> | 2019-08-19 17:18:01 -0700 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2019-08-19 21:54:16 -0700 |
| commit | 29d3c1c8dfe752c01b7115ecd5a3142b232a38e1 (patch) | |
| tree | 9a42db9e64c08db645dcf9689344d4f718b4d518 /include/linux/ima.h | |
| parent | b0c8fdc7fdb77586c3d1937050925b960743306e (diff) | |
| download | lwn-29d3c1c8dfe752c01b7115ecd5a3142b232a38e1.tar.gz lwn-29d3c1c8dfe752c01b7115ecd5a3142b232a38e1.zip | |
kexec: Allow kexec_file() with appropriate IMA policy when locked down
Systems in lockdown mode should block the kexec of untrusted kernels.
For x86 and ARM we can ensure that a kernel is trustworthy by validating
a PE signature, but this isn't possible on other architectures. On those
platforms we can use IMA digital signatures instead. Add a function to
determine whether IMA has or will verify signatures for a given event type,
and if so permit kexec_file() even if the kernel is otherwise locked down.
This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set
in order to prevent an attacker from loading additional keys at runtime.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: linux-integrity@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'include/linux/ima.h')
| -rw-r--r-- | include/linux/ima.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/ima.h b/include/linux/ima.h index 00036d2f57c3..8e2f324fb901 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -129,4 +129,13 @@ static inline int ima_inode_removexattr(struct dentry *dentry, return 0; } #endif /* CONFIG_IMA_APPRAISE */ + +#if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING) +extern bool ima_appraise_signature(enum kernel_read_file_id func); +#else +static inline bool ima_appraise_signature(enum kernel_read_file_id func) +{ + return false; +} +#endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */ #endif /* _LINUX_IMA_H */ |