This is a note to let you know that I've just added the patch titled
evm: properly handle INTEGRITY_NOXATTRS EVM status
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
evm-properly-handle-integrity_noxattrs-evm-status.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 3dcbad52cf18c3c379e96b992d22815439ebbe53 Mon Sep 17 00:00:00 2001
From: Dmitry Kasatkin <[email protected]>
Date: Tue, 2 Sep 2014 16:31:43 +0300
Subject: evm: properly handle INTEGRITY_NOXATTRS EVM status
From: Dmitry Kasatkin <[email protected]>
commit 3dcbad52cf18c3c379e96b992d22815439ebbe53 upstream.
Unless an LSM labels a file during d_instantiate(), newly created
files are not labeled with an initial security.evm xattr, until
the file closes. EVM, before allowing a protected, security xattr
to be written, verifies the existing 'security.evm' value is good.
For newly created files without a security.evm label, this
verification prevents writing any protected, security xattrs,
until the file closes.
Following is the example when this happens:
fd = open("foo", O_CREAT | O_WRONLY, 0644);
setxattr("foo", "security.SMACK64", value, sizeof(value), 0);
close(fd);
While INTEGRITY_NOXATTRS status is handled in other places, such
as evm_inode_setattr(), it does not handle it in all cases in
evm_protect_xattr(). By limiting the use of INTEGRITY_NOXATTRS to
newly created files, we can now allow setting "protected" xattrs.
Changelog:
- limit the use of INTEGRITY_NOXATTRS to IMA identified new files
Signed-off-by: Dmitry Kasatkin <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
security/integrity/evm/evm_main.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -269,6 +269,13 @@ static int evm_protect_xattr(struct dent
goto out;
}
evm_status = evm_verify_current_integrity(dentry);
+ if (evm_status == INTEGRITY_NOXATTRS) {
+ struct integrity_iint_cache *iint;
+
+ iint = integrity_iint_find(dentry->d_inode);
+ if (iint && (iint->flags & IMA_NEW_FILE))
+ return 0;
+ }
out:
if (evm_status != INTEGRITY_PASS)
integrity_audit_msg(AUDIT_INTEGRITY_METADATA, dentry->d_inode,
Patches currently in stable-queue which might be from [email protected] are
queue-3.14/evm-properly-handle-integrity_noxattrs-evm-status.patch
queue-3.14/evm-check-xattr-value-length-and-type-in-evm_inode_setxattr.patch
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