[PATCH ima-evm-utils v5 03/17] Log and reset 'errno' on lsetxattr failure

[Mimi Zohar <zohar@xxxxxxxxxxxxx>]

Writing either security.ima hashes or security.evm hmacs from userspace
will fail regardless of the IMA or EVM fix mode.  In fix mode, 'touch'
will force security.ima and security.evm to be updated.

Make the setxattr error messages more explicit and clear errno.

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
 src/evmctl.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/evmctl.c b/src/evmctl.c
index 54123bf20f03..53af4d2cb961 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -572,7 +572,8 @@ static int sign_evm(const char *file, const char *key)
 	if (xattr) {
 		err = lsetxattr(file, xattr_evm, sig, len, 0);
 		if (err < 0) {
-			log_err("setxattr failed: %s\n", file);
+			log_errno_reset(LOG_ERR, "Setting EVM xattr failed: %s",
+					file);
 			return err;
 		}
 	}
@@ -615,7 +616,9 @@ static int hash_ima(const char *file)
 	if (xattr) {
 		err = lsetxattr(file, xattr_ima, hash, len, 0);
 		if (err < 0) {
-			log_err("setxattr failed: %s\n", file);
+			log_errno_reset(LOG_ERR,
+					"Setting IMA hash xattr failed: %s",
+					file);
 			return err;
 		}
 	}
@@ -652,7 +655,9 @@ static int sign_ima(const char *file, const char *key)
 	if (xattr) {
 		err = lsetxattr(file, xattr_ima, sig, len, 0);
 		if (err < 0) {
-			log_err("setxattr failed: %s\n", file);
+			log_errno_reset(LOG_ERR,
+					"Setting IMA sig xattr failed: %s",
+					file);
 			return err;
 		}
 	}
@@ -1125,7 +1130,8 @@ static int setxattr_ima(const char *file, char *sig_file)
 
 	err = lsetxattr(file, xattr_ima, sig, len, 0);
 	if (err < 0)
-		log_err("setxattr failed: %s\n", file);
+		log_errno_reset(LOG_ERR, "Setting IMA sig xattr failed: %s",
+				file);
 	free(sig);
 	return err;
 }
@@ -1323,7 +1329,9 @@ static int hmac_evm(const char *file, const char *key)
 		sig[0] = EVM_XATTR_HMAC;
 		err = lsetxattr(file, xattr_evm, sig, len + 1, 0);
 		if (err < 0) {
-			log_err("setxattr failed: %s\n", file);
+			log_errno_reset(LOG_ERR,
+					"Setting EVM hmac xattr failed: %s",
+					file);
 			return err;
 		}
 	}
-- 
2.31.1