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author | Elena Reshetova <elena.reshetova@intel.com> | 2017-09-08 16:17:45 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:51 -0700 |
commit | 9405c03ee778cd3e353e55fff6e16dfdd9609c02 (patch) | |
tree | 197d334b72ecc283c04b3fd80fbf2d5021acc249 /ipc | |
parent | f74370b86ec1e0ee8a56ba838efe78e21d8dba23 (diff) | |
download | lwn-9405c03ee778cd3e353e55fff6e16dfdd9609c02.tar.gz lwn-9405c03ee778cd3e353e55fff6e16dfdd9609c02.zip |
ipc: convert kern_ipc_perm.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.
Link: http://lkml.kernel.org/r/1499417992-3238-4-git-send-email-elena.reshetova@intel.com
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>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: <arozansk@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
-rw-r--r-- | ipc/util.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/ipc/util.c b/ipc/util.c index 1a2cb02467ab..069bb22c9f64 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -232,7 +232,7 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size) idr_preload(GFP_KERNEL); - atomic_set(&new->refcount, 1); + refcount_set(&new->refcount, 1); spin_lock_init(&new->lock); new->deleted = false; rcu_read_lock(); @@ -397,13 +397,13 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) int ipc_rcu_getref(struct kern_ipc_perm *ptr) { - return atomic_inc_not_zero(&ptr->refcount); + return refcount_inc_not_zero(&ptr->refcount); } void ipc_rcu_putref(struct kern_ipc_perm *ptr, void (*func)(struct rcu_head *head)) { - if (!atomic_dec_and_test(&ptr->refcount)) + if (!refcount_dec_and_test(&ptr->refcount)) return; call_rcu(&ptr->rcu, func); |