net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/calipso.h b/include/net/calipso.h
index b1b30cd36601564a9de50be99c64cf8e81171e54..5f95b11a04bff7f9a65f18299b4e63647625c88a 100644 (file)
--- a/include/net/calipso.h
+++ b/include/net/calipso.h
@@ -38,7 +38,7 @@
 #include <linux/skbuff.h>
 #include <net/netlabel.h>
 #include <net/request_sock.h>
-#include <linux/atomic.h>
+#include <linux/refcount.h>
 #include <asm/unaligned.h>
 
 /* known doi values */
@@ -57,7 +57,7 @@ struct calipso_doi {
        u32 doi;
        u32 type;
 
-       atomic_t refcount;
+       refcount_t refcount;
        struct list_head list;
        struct rcu_head rcu;
 };

diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index 44067521e7cd56e84870fb1a8209b68349ac22f4..1323b9679cf718d0023bf5880dcd60fb8602d9db 100644 (file)
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -338,7 +338,7 @@ static struct calipso_doi *calipso_doi_search(u32 doi)
        struct calipso_doi *iter;
 
        list_for_each_entry_rcu(iter, &calipso_doi_list, list)
-               if (iter->doi == doi && atomic_read(&iter->refcount))
+               if (iter->doi == doi && refcount_read(&iter->refcount))
                        return iter;
        return NULL;
 }
@@ -370,7 +370,7 @@ static int calipso_doi_add(struct calipso_doi *doi_def,
        if (doi_def->doi == CALIPSO_DOI_UNKNOWN)
                goto doi_add_return;
 
-       atomic_set(&doi_def->refcount, 1);
+       refcount_set(&doi_def->refcount, 1);
 
        spin_lock(&calipso_doi_list_lock);
        if (calipso_doi_search(doi_def->doi)) {
@@ -458,7 +458,7 @@ static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info)
                ret_val = -ENOENT;
                goto doi_remove_return;
        }
-       if (!atomic_dec_and_test(&doi_def->refcount)) {
+       if (!refcount_dec_and_test(&doi_def->refcount)) {
                spin_unlock(&calipso_doi_list_lock);
                ret_val = -EBUSY;
                goto doi_remove_return;
@@ -499,7 +499,7 @@ static struct calipso_doi *calipso_doi_getdef(u32 doi)
        doi_def = calipso_doi_search(doi);
        if (!doi_def)
                goto doi_getdef_return;
-       if (!atomic_inc_not_zero(&doi_def->refcount))
+       if (!refcount_inc_not_zero(&doi_def->refcount))
                doi_def = NULL;
 
 doi_getdef_return:
@@ -520,7 +520,7 @@ static void calipso_doi_putdef(struct calipso_doi *doi_def)
        if (!doi_def)
                return;
 
-       if (!atomic_dec_and_test(&doi_def->refcount))
+       if (!refcount_dec_and_test(&doi_def->refcount))
                return;
        spin_lock(&calipso_doi_list_lock);
        list_del_rcu(&doi_def->list);
@@ -553,7 +553,7 @@ static int calipso_doi_walk(u32 *skip_cnt,
 
        rcu_read_lock();
        list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list)
-               if (atomic_read(&iter_doi->refcount) > 0) {
+               if (refcount_read(&iter_doi->refcount) > 0) {
                        if (doi_cnt++ < *skip_cnt)
                                continue;
                        ret_val = callback(iter_doi, cb_arg);