[RFC][PATCH 2/4] ima: make a copy of template_fmt in template_desc_init_fields()

[Roberto Sassu]

This patch makes a copy of the 'template_fmt' function argument so that
the latter will not be modified by strsep(), which does the splitting by
replacing the given separator with '\0'.

Signed-off-by: Roberto Sassu <roberto.sa...@polito.it>
---
 security/integrity/ima/ima_template.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima_template.c 
b/security/integrity/ima/ima_template.c
index 7bcff5c..bb33576 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -113,13 +113,19 @@ static int template_desc_init_fields(char *template_fmt,
                                     struct ima_template_field ***fields,
                                     int *num_fields)
 {
-       char *c, *template_fmt_ptr = template_fmt;
+       char *c, *template_fmt_ptr, *template_fmt_copy = NULL;
        int template_num_fields = template_fmt_size(template_fmt);
        int i, result = 0;
 
        if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX)
                return -EINVAL;
 
+       /* copying is needed as strsep() modifies the original buffer */
+       template_fmt_copy = kstrdup(template_fmt, GFP_KERNEL);
+       if (template_fmt_copy == NULL)
+               return -ENOMEM;
+
+       template_fmt_ptr = template_fmt_copy;
        *fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL);
        if (*fields == NULL) {
                result = -ENOMEM;
@@ -139,6 +145,7 @@ static int template_desc_init_fields(char *template_fmt,
        *num_fields = i;
        return 0;
 out:
+       kfree(template_fmt_copy);
        kfree(*fields);
        *fields = NULL;
        return result;
-- 
1.8.1.4

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