From mboxrd@z Thu Jan 1 00:00:00 1970 From: mic@digikod.net (=?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?=) Date: Sat, 29 Apr 2017 21:02:57 +0200 Subject: [PATCH v1] LSM: Enable multiple calls to security_add_hooks() for the same LSM Message-ID: <20170429190257.27137-1-mic@digikod.net> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org Check if the registering LSM already registered hooks just before. This enable to split hook declarations into multiple files without registering multiple time the same LSM name, starting from commit d69dece5f5b6 ("LSM: Add /sys/kernel/security/lsm"). Signed-off-by: Micka?l Sala?n Cc: Casey Schaufler Cc: James Morris Cc: Kees Cook Cc: Serge E. Hallyn Link: https://lkml.kernel.org/r/ccad825b-7a58-e499-e51b-bd7c98581afe at schaufler-ca.com --- security/security.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/security/security.c b/security/security.c index 549bddcc2116..6be65050b268 100644 --- a/security/security.c +++ b/security/security.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #define MAX_LSM_EVM_XATTR 2 @@ -86,6 +87,32 @@ static int __init choose_lsm(char *str) } __setup("security=", choose_lsm); +static bool match_last_lsm(const char *list, const char *last) +{ + size_t list_len, last_len, i; + + if (!list || !last) + return false; + list_len = strlen(list); + last_len = strlen(last); + if (!last_len || !list_len) + return false; + if (last_len > list_len) + return false; + + for (i = 0; i < last_len; i++) { + if (list[list_len - 1 - i] != last[last_len - 1 - i]) + return false; + } + /* Check if last_len == list_len */ + if (i == list_len) + return true; + /* Check if it is a full name */ + if (list[list_len - 1 - i] == ',') + return true; + return false; +} + static int lsm_append(char *new, char **result) { char *cp; @@ -93,6 +120,9 @@ static int lsm_append(char *new, char **result) if (*result == NULL) { *result = kstrdup(new, GFP_KERNEL); } else { + /* Check if it is the last registered name */ + if (match_last_lsm(*result, new)) + return 0; cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new); if (cp == NULL) return -ENOMEM; -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info@ http://vger.kernel.org/majordomo-info.html