| Message ID | 1477017898-10375-8-git-send-email-bauerman@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 21, 2016 at 5:44 AM, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> wrote: > From: Mimi Zohar <zohar@linux.vnet.ibm.com> > > The builtin and single custom templates are currently stored in an > array. In preparation for being able to restore a measurement list > containing multiple builtin/custom templates, this patch stores the > builtin and custom templates as a linked list. This will permit > defining more than one custom template per boot. > > Changelog v4: > - fix "spinlock bad magic" BUG - reported by Dmitry Vyukov > > Changelog v3: > - initialize template format list in ima_template_desc_current(), as it > might be called during __setup before normal initialization. (kernel > test robot) > - remove __init annotation of ima_init_template_list() > > Changelog v2: > - fix lookup_template_desc() preemption imbalance (kernel test robot) > > Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> > --- > security/integrity/ima/ima.h | 2 ++ > security/integrity/ima/ima_main.c | 1 + > security/integrity/ima/ima_template.c | 52 +++++++++++++++++++++++++++-------- > 3 files changed, 44 insertions(+), 11 deletions(-) > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index 139dec67dcbf..6b0540ad189f 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -85,6 +85,7 @@ struct ima_template_field { > > /* IMA template descriptor definition */ > struct ima_template_desc { > + struct list_head list; > char *name; > char *fmt; > int num_fields; > @@ -146,6 +147,7 @@ int ima_restore_measurement_list(loff_t bufsize, void *buf); > int ima_measurements_show(struct seq_file *m, void *v); > unsigned long ima_get_binary_runtime_size(void); > int ima_init_template(void); > +void ima_init_template_list(void); > > /* > * used to protect h_table and sha_table > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 423d111b3b94..50818c60538b 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -418,6 +418,7 @@ static int __init init_ima(void) > { > int error; > > + ima_init_template_list(); > hash_setup(CONFIG_IMA_DEFAULT_HASH); > error = ima_init(); > if (!error) { > diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c > index 37f972cb05fe..c0d808c20c40 100644 > --- a/security/integrity/ima/ima_template.c > +++ b/security/integrity/ima/ima_template.c > @@ -15,16 +15,20 @@ > > #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > +#include <linux/rculist.h> > #include "ima.h" > #include "ima_template_lib.h" > > -static struct ima_template_desc defined_templates[] = { > +static struct ima_template_desc builtin_templates[] = { > {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT}, > {.name = "ima-ng", .fmt = "d-ng|n-ng"}, > {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"}, > {.name = "", .fmt = ""}, /* placeholder for a custom format */ > }; > > +static LIST_HEAD(defined_templates); > +static DEFINE_SPINLOCK(template_list); > + > static struct ima_template_field supported_fields[] = { > {.field_id = "d", .field_init = ima_eventdigest_init, > .field_show = ima_show_template_digest}, > @@ -53,6 +57,8 @@ static int __init ima_template_setup(char *str) > if (ima_template) > return 1; > > + ima_init_template_list(); > + > /* > * Verify that a template with the supplied name exists. > * If not, use CONFIG_IMA_DEFAULT_TEMPLATE. > @@ -81,7 +87,7 @@ __setup("ima_template=", ima_template_setup); > > static int __init ima_template_fmt_setup(char *str) > { > - int num_templates = ARRAY_SIZE(defined_templates); > + int num_templates = ARRAY_SIZE(builtin_templates); > > if (ima_template) > return 1; > @@ -92,22 +98,28 @@ static int __init ima_template_fmt_setup(char *str) > return 1; > } > > - defined_templates[num_templates - 1].fmt = str; > - ima_template = defined_templates + num_templates - 1; > + builtin_templates[num_templates - 1].fmt = str; > + ima_template = builtin_templates + num_templates - 1; > + > return 1; > } > __setup("ima_template_fmt=", ima_template_fmt_setup); > > static struct ima_template_desc *lookup_template_desc(const char *name) > { > - int i; > + struct ima_template_desc *template_desc; > + int found = 0; > > - for (i = 0; i < ARRAY_SIZE(defined_templates); i++) { > - if (strcmp(defined_templates[i].name, name) == 0) > - return defined_templates + i; > + rcu_read_lock(); > + list_for_each_entry_rcu(template_desc, &defined_templates, list) { > + if ((strcmp(template_desc->name, name) == 0) || > + (strcmp(template_desc->fmt, name) == 0)) { > + found = 1; > + break; > + } > } > - > - return NULL; > + rcu_read_unlock(); > + return found ? template_desc : NULL; > } > > static struct ima_template_field *lookup_template_field(const char *field_id) > @@ -183,11 +195,29 @@ static int template_desc_init_fields(const char *template_fmt, > return 0; > } > > +void ima_init_template_list(void) > +{ > + int i; > + > + if (!list_empty(&defined_templates)) > + return; > + > + spin_lock(&template_list); > + for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) { > + list_add_tail_rcu(&builtin_templates[i].list, > + &defined_templates); > + } > + spin_unlock(&template_list); > + synchronize_rcu(); Btw, what is the purpose of synchronize rcu here? i think it make sense before deleting the object, like: -------------------------------- list_del_rcu(&p->list); spin_unlock(&listmutex); synchronize_rcu(); kfree(p); -------------------------------- I think it is never deleted. There is another similar place in the same file... > +} > + > struct ima_template_desc *ima_template_desc_current(void) > { > - if (!ima_template) > + if (!ima_template) { > + ima_init_template_list(); > ima_template = > lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE); > + } > return ima_template; > } > > -- > 2.7.4 > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Linux-ima-devel mailing list > Linux-ima-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-ima-devel
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 139dec67dcbf..6b0540ad189f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -85,6 +85,7 @@ struct ima_template_field { /* IMA template descriptor definition */ struct ima_template_desc { + struct list_head list; char *name; char *fmt; int num_fields; @@ -146,6 +147,7 @@ int ima_restore_measurement_list(loff_t bufsize, void *buf); int ima_measurements_show(struct seq_file *m, void *v); unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); +void ima_init_template_list(void); /* * used to protect h_table and sha_table diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 423d111b3b94..50818c60538b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -418,6 +418,7 @@ static int __init init_ima(void) { int error; + ima_init_template_list(); hash_setup(CONFIG_IMA_DEFAULT_HASH); error = ima_init(); if (!error) { diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 37f972cb05fe..c0d808c20c40 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -15,16 +15,20 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/rculist.h> #include "ima.h" #include "ima_template_lib.h" -static struct ima_template_desc defined_templates[] = { +static struct ima_template_desc builtin_templates[] = { {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT}, {.name = "ima-ng", .fmt = "d-ng|n-ng"}, {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"}, {.name = "", .fmt = ""}, /* placeholder for a custom format */ }; +static LIST_HEAD(defined_templates); +static DEFINE_SPINLOCK(template_list); + static struct ima_template_field supported_fields[] = { {.field_id = "d", .field_init = ima_eventdigest_init, .field_show = ima_show_template_digest}, @@ -53,6 +57,8 @@ static int __init ima_template_setup(char *str) if (ima_template) return 1; + ima_init_template_list(); + /* * Verify that a template with the supplied name exists. * If not, use CONFIG_IMA_DEFAULT_TEMPLATE. @@ -81,7 +87,7 @@ __setup("ima_template=", ima_template_setup); static int __init ima_template_fmt_setup(char *str) { - int num_templates = ARRAY_SIZE(defined_templates); + int num_templates = ARRAY_SIZE(builtin_templates); if (ima_template) return 1; @@ -92,22 +98,28 @@ static int __init ima_template_fmt_setup(char *str) return 1; } - defined_templates[num_templates - 1].fmt = str; - ima_template = defined_templates + num_templates - 1; + builtin_templates[num_templates - 1].fmt = str; + ima_template = builtin_templates + num_templates - 1; + return 1; } __setup("ima_template_fmt=", ima_template_fmt_setup); static struct ima_template_desc *lookup_template_desc(const char *name) { - int i; + struct ima_template_desc *template_desc; + int found = 0; - for (i = 0; i < ARRAY_SIZE(defined_templates); i++) { - if (strcmp(defined_templates[i].name, name) == 0) - return defined_templates + i; + rcu_read_lock(); + list_for_each_entry_rcu(template_desc, &defined_templates, list) { + if ((strcmp(template_desc->name, name) == 0) || + (strcmp(template_desc->fmt, name) == 0)) { + found = 1; + break; + } } - - return NULL; + rcu_read_unlock(); + return found ? template_desc : NULL; } static struct ima_template_field *lookup_template_field(const char *field_id) @@ -183,11 +195,29 @@ static int template_desc_init_fields(const char *template_fmt, return 0; } +void ima_init_template_list(void) +{ + int i; + + if (!list_empty(&defined_templates)) + return; + + spin_lock(&template_list); + for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) { + list_add_tail_rcu(&builtin_templates[i].list, + &defined_templates); + } + spin_unlock(&template_list); + synchronize_rcu(); +} + struct ima_template_desc *ima_template_desc_current(void) { - if (!ima_template) + if (!ima_template) { + ima_init_template_list(); ima_template = lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE); + } return ima_template; }