This is a note to let you know that I've just added the patch titled
evm: don't copy up 'security.evm' xattr
to the 6.6-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-don-t-copy-up-security.evm-xattr.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bb937b496f3f12b6c3d3154e7ff955070d22c98b
Author: Mimi Zohar <zohar@xxxxxxxxxxxxx>
Date: Tue Dec 12 06:12:43 2023 -0500
evm: don't copy up 'security.evm' xattr
[ Upstream commit 40ca4ee3136d2d09977d1cab8c0c0e1582c3359d ]
The security.evm HMAC and the original file signatures contain
filesystem specific data. As a result, the HMAC and signature
are not the same on the stacked and backing filesystems.
Don't copy up 'security.evm'.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/evm.h b/include/linux/evm.h
index 01fc495a83e27..36ec884320d9f 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -31,6 +31,7 @@ extern void evm_inode_post_setxattr(struct dentry *dentry,
const char *xattr_name,
const void *xattr_value,
size_t xattr_value_len);
+extern int evm_inode_copy_up_xattr(const char *name);
extern int evm_inode_removexattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *xattr_name);
extern void evm_inode_post_removexattr(struct dentry *dentry,
@@ -117,6 +118,11 @@ static inline void evm_inode_post_setxattr(struct dentry *dentry,
return;
}
+static inline int evm_inode_copy_up_xattr(const char *name)
+{
+ return 0;
+}
+
static inline int evm_inode_removexattr(struct mnt_idmap *idmap,
struct dentry *dentry,
const char *xattr_name)
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index ff9a939dad8e4..2393230c03aa3 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -864,6 +864,13 @@ void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
evm_update_evmxattr(dentry, NULL, NULL, 0);
}
+int evm_inode_copy_up_xattr(const char *name)
+{
+ if (strcmp(name, XATTR_NAME_EVM) == 0)
+ return 1; /* Discard */
+ return -EOPNOTSUPP;
+}
+
/*
* evm_inode_init_security - initializes security.evm HMAC value
*/
diff --git a/security/security.c b/security/security.c
index dd26f21b2244b..b6144833c7a8e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2539,7 +2539,7 @@ int security_inode_copy_up_xattr(const char *name)
return rc;
}
- return LSM_RET_DEFAULT(inode_copy_up_xattr);
+ return evm_inode_copy_up_xattr(name);
}
EXPORT_SYMBOL(security_inode_copy_up_xattr);
