From cdef685be5b4ae55c3959289e72d520402839c29 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 14 May 2021 17:27:47 +0200 Subject: evm: Allow xattr/attr operations for portable signatures If files with portable signatures are copied from one location to another or are extracted from an archive, verification can temporarily fail until all xattrs/attrs are set in the destination. Only portable signatures may be moved or copied from one file to another, as they don't depend on system-specific information such as the inode generation. Instead portable signatures must include security.ima. Unlike other security.evm types, EVM portable signatures are also immutable. Thus, it wouldn't be a problem to allow xattr/attr operations when verification fails, as portable signatures will never be replaced with the HMAC on possibly corrupted xattrs/attrs. This patch first introduces a new integrity status called INTEGRITY_FAIL_IMMUTABLE, that allows callers of evm_verify_current_integrity() to detect that a portable signature didn't pass verification and then adds an exception in evm_protect_xattr() and evm_inode_setattr() for this status and returns 0 instead of -EPERM. Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar --- include/linux/integrity.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/integrity.h b/include/linux/integrity.h index 2271939c5c31..2ea0f2f65ab6 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -13,6 +13,7 @@ enum integrity_status { INTEGRITY_PASS = 0, INTEGRITY_PASS_IMMUTABLE, INTEGRITY_FAIL, + INTEGRITY_FAIL_IMMUTABLE, INTEGRITY_NOLABEL, INTEGRITY_NOXATTRS, INTEGRITY_UNKNOWN, -- cgit v1.3-18-gd494