Messages in this thread | | | Date | Fri, 22 Nov 2013 17:36:59 +0100 | From | Roberto Sassu <> | Subject | Re: [BUG] 3ce1217d6cd5 ima patch causes s390 to crash on boot |
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On 11/22/2013 05:35 PM, Heiko Carstens wrote: > On Fri, Nov 22, 2013 at 05:23:49PM +0100, Roberto Sassu wrote: >> Another problem that I found is that strsep() >> modifies the source buffer by replacing the separator >> character with '\0'. In particular, this function >> modifies static data initialized at the beginning >> of the ima_template.c file. Maybe, this is causing >> the kernel panic. I already sent a patch to fix this >> problem (attached to the email) even if it is not >> supposed to land on the 3.13 kernel. Let me know >> if this fixes the issue. Otherwise, I will check >> the code more in depth. > > With your patch below applied the kernel boots again. > So it should go into 3.13 (or a different fix). >
Ok, good. Yes, we will apply this patch to the 3.13 kernel.
> Thanks!
No problem.
Roberto
> >> From 2d3aa1c0328c44ecc3af7de162791c8cddfb6dfd Mon Sep 17 00:00:00 2001 >> From: Roberto Sassu <roberto.sassu@polito.it> >> Date: Wed, 6 Nov 2013 13:51:35 +0100 >> Subject: [RFC][PATCH 2/4] 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'. >> >> Signed-off-by: Roberto Sassu <roberto.sassu@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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