net, ipv6: convert ipv6_txoptions.refcnt 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>
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committed by
David S. Miller

parent
25f4535a94
commit
0aeea21ada
@@ -16,6 +16,7 @@
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#include <linux/ipv6.h>
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#include <linux/hardirq.h>
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#include <linux/jhash.h>
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#include <linux/refcount.h>
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#include <net/if_inet6.h>
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#include <net/ndisc.h>
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#include <net/flow.h>
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@@ -203,7 +204,7 @@ extern rwlock_t ip6_ra_lock;
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*/
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struct ipv6_txoptions {
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atomic_t refcnt;
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refcount_t refcnt;
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/* Length of this structure */
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int tot_len;
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@@ -265,7 +266,7 @@ static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
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rcu_read_lock();
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opt = rcu_dereference(np->opt);
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if (opt) {
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if (!atomic_inc_not_zero(&opt->refcnt))
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if (!refcount_inc_not_zero(&opt->refcnt))
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opt = NULL;
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else
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opt = rcu_pointer_handoff(opt);
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@@ -276,7 +277,7 @@ static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
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static inline void txopt_put(struct ipv6_txoptions *opt)
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{
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if (opt && atomic_dec_and_test(&opt->refcnt))
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if (opt && refcount_dec_and_test(&opt->refcnt))
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kfree_rcu(opt, rcu);
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}
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