From 5e6f29a2ed378753f2f9a5210e7ef8bdaf6830ef Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 17 Aug 2022 17:18:42 -0400 Subject: [PATCH] ima: fix blocking of security.ima xattrs of unsupported algorithms [ Upstream commit 5926586f291b53cb8a0c9631fc19489be1186e2d ] Limit validating the hash algorithm to just security.ima xattr, not the security.evm xattr or any of the protected EVM security xattrs, nor posix acls. Fixes: 50f742dd9147 ("IMA: block writes of the security.ima xattr with unsupported algorithms") Reported-by: Christian Brauner Acked-by: Christian Brauner (Microsoft) Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_appraise.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index bde74fcecee3..3e0fbbd99534 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -750,22 +750,26 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, const struct evm_ima_xattr_data *xvalue = xattr_value; int digsig = 0; int result; + int err; result = ima_protect_xattr(dentry, xattr_name, xattr_value, xattr_value_len); if (result == 1) { if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) return -EINVAL; + + err = validate_hash_algo(dentry, xvalue, xattr_value_len); + if (err) + return err; + digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG); } else if (!strcmp(xattr_name, XATTR_NAME_EVM) && xattr_value_len > 0) { digsig = (xvalue->type == EVM_XATTR_PORTABLE_DIGSIG); } if (result == 1 || evm_revalidate_status(xattr_name)) { - result = validate_hash_algo(dentry, xvalue, xattr_value_len); - if (result) - return result; - ima_reset_appraise_flags(d_backing_inode(dentry), digsig); + if (result == 1) + result = 0; } return result; }