Messages in this thread | | | Date | Fri, 22 Nov 2013 17:35:02 +0100 | From | Heiko Carstens <> | Subject | Re: [BUG] 3ce1217d6cd5 ima patch causes s390 to crash on boot |
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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).
Thanks!
> 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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