From 27c0008c75ddfa759d5645ecbc3f86e0de37472a Mon Sep 17 00:00:00 2001 From: Eric Seppanen Date: Wed, 20 Nov 2013 14:19:52 -0800 Subject: [PATCH] iscsi-target: chap auth shouldn't match username with trailing garbage commit 86784c6bdeeef78eed94d298be7a8879f6a97ee2 upstream. In iSCSI negotiations with initiator CHAP enabled, usernames with trailing garbage are permitted, because the string comparison only checks the strlen of the configured username. e.g. "usernameXXXXX" will be permitted to match "username". Just check one more byte so the trailing null char is also matched. Signed-off-by: Eric Seppanen Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/iscsi/iscsi_target_auth.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c index a0fc7b9..b54f6ec 100644 --- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -174,6 +174,7 @@ static int chap_server_compute_md5( unsigned char client_digest[MD5_SIGNATURE_SIZE]; unsigned char server_digest[MD5_SIGNATURE_SIZE]; unsigned char chap_n[MAX_CHAP_N_SIZE], chap_r[MAX_RESPONSE_LENGTH]; + size_t compare_len; struct iscsi_chap *chap = conn->auth_protocol; struct crypto_hash *tfm; struct hash_desc desc; @@ -212,7 +213,9 @@ static int chap_server_compute_md5( goto out; } - if (memcmp(chap_n, auth->userid, strlen(auth->userid)) != 0) { + /* Include the terminating NULL in the compare */ + compare_len = strlen(auth->userid) + 1; + if (strncmp(chap_n, auth->userid, compare_len) != 0) { pr_err("CHAP_N values do not match!\n"); goto out; } -- 2.7.4