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authorRoberto Sassu <roberto.sassu@polito.it>2013-11-25 20:18:52 +0100
committerMimi Zohar <zohar@linux.vnet.ibm.com>2013-11-25 15:05:33 -0500
commitdbc335d2dc3c437649eb6b39f4e9aee2a13eb0af (patch)
treeb070f9d96f16ae2abf4c6a5b824d2b6c82716da2 /security/integrity
parent3e8e5503a33577d89bdb7469b851b11f507bbed6 (diff)
downloadlinux-stericsson-dbc335d2dc3c437649eb6b39f4e9aee2a13eb0af.tar.gz
ima: make a copy of template_fmt in template_desc_init_fields()
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'.  IMA: No TPM chip found, activating TPM-bypass!  Unable to handle kernel pointer dereference at virtual kernel address 0000000000842000  Oops: 0004 [#1] SMP  Modules linked in:  CPU: 3 PID: 1 Comm: swapper/0 Not tainted 3.12.0-rc2-00098-g3ce1217d6cd5 #17  task: 000000003ffa0000 ti: 000000003ff84000 task.ti: 000000003ff84000  Krnl PSW : 0704e00180000000 000000000044bf88 (strsep+0x7c/0xa0)             R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3  Krnl GPRS: 000000000000007c 000000000000007c 000000003ff87d90 0000000000821fd8             0000000000000000 000000000000007c 0000000000aa37e0 0000000000aa9008             0000000000000051 0000000000a114d8 0000000100000002 0000000000842bde             0000000000842bdf 00000000006f97f0 000000000040062c 000000003ff87cf0  Krnl Code: 000000000044bf7c: a7f4000a           brc     15,44bf90             000000000044bf80: b90200cc           ltgr    %r12,%r12            #000000000044bf84: a7840006           brc     8,44bf90            >000000000044bf88: 9200c000           mvi     0(%r12),0             000000000044bf8c: 41c0c001           la      %r12,1(%r12)             000000000044bf90: e3c020000024       stg     %r12,0(%r2)             000000000044bf96: b904002b           lgr     %r2,%r11             000000000044bf9a: ebbcf0700004       lmg     %r11,%r12,112(%r15)  Call Trace:  ([<00000000004005fe>] ima_init_template+0xa2/0x1bc)   [<0000000000a7c896>] ima_init+0x7a/0xa8   [<0000000000a7c938>] init_ima+0x24/0x40   [<00000000001000e8>] do_one_initcall+0x68/0x128   [<0000000000a4eb56>] kernel_init_freeable+0x20a/0x2b4   [<00000000006a1ff4>] kernel_init+0x30/0x178   [<00000000006b69fe>] kernel_thread_starter+0x6/0xc   [<00000000006b69f8>] kernel_thread_starter+0x0/0xc  Last Breaking-Event-Address:   [<000000000044bf42>] strsep+0x36/0xa0 Fixes commit: adf53a7 ima: new templates management mechanism Changelog v1: - make template_fmt 'const char *' (reported-by James Morris) - fix kstrdup memory leak (reported-by James Morris) Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'security/integrity')
-rw-r--r--security/integrity/ima/ima_template.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 4e5da990630b..913e1927f916 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -90,7 +90,7 @@ static struct ima_template_field *lookup_template_field(const char *field_id)
return NULL;
}
-static int template_fmt_size(char *template_fmt)
+static int template_fmt_size(const char *template_fmt)
{
char c;
int template_fmt_len = strlen(template_fmt);
@@ -106,23 +106,28 @@ static int template_fmt_size(char *template_fmt)
return j + 1;
}
-static int template_desc_init_fields(char *template_fmt,
+static int template_desc_init_fields(const char *template_fmt,
struct ima_template_field ***fields,
int *num_fields)
{
- char *c, *template_fmt_ptr = template_fmt;
+ char *c, *template_fmt_copy;
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;
+
*fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL);
if (*fields == NULL) {
result = -ENOMEM;
goto out;
}
- for (i = 0; (c = strsep(&template_fmt_ptr, "|")) != NULL &&
+ for (i = 0; (c = strsep(&template_fmt_copy, "|")) != NULL &&
i < template_num_fields; i++) {
struct ima_template_field *f = lookup_template_field(c);
@@ -133,10 +138,12 @@ static int template_desc_init_fields(char *template_fmt,
(*fields)[i] = f;
}
*num_fields = i;
- return 0;
out:
- kfree(*fields);
- *fields = NULL;
+ if (result < 0) {
+ kfree(*fields);
+ *fields = NULL;
+ }
+ kfree(template_fmt_copy);
return result;
}