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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-09-08 16:17:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:51 -0700 |
| commit | f74370b86ec1e0ee8a56ba838efe78e21d8dba23 (patch) | |
| tree | 5ecda3120c2c13915cf8e1d2ee570062465479ef /ipc/sem.c | |
| parent | a2e0602c36ed9fe042714694dd5a889ecd8cb556 (diff) | |
| download | lwn-f74370b86ec1e0ee8a56ba838efe78e21d8dba23.tar.gz lwn-f74370b86ec1e0ee8a56ba838efe78e21d8dba23.zip | |
ipc: convert sem_undo_list.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.
Link: http://lkml.kernel.org/r/1499417992-3238-3-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/sem.c')
| -rw-r--r-- | ipc/sem.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index c6c50370504c..31b138b9e756 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -122,7 +122,7 @@ struct sem_undo { * that may be shared among all a CLONE_SYSVSEM task group. */ struct sem_undo_list { - atomic_t refcnt; + refcount_t refcnt; spinlock_t lock; struct list_head list_proc; }; @@ -1642,7 +1642,7 @@ static inline int get_undo_list(struct sem_undo_list **undo_listp) if (undo_list == NULL) return -ENOMEM; spin_lock_init(&undo_list->lock); - atomic_set(&undo_list->refcnt, 1); + refcount_set(&undo_list->refcnt, 1); INIT_LIST_HEAD(&undo_list->list_proc); current->sysvsem.undo_list = undo_list; @@ -2041,7 +2041,7 @@ int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) error = get_undo_list(&undo_list); if (error) return error; - atomic_inc(&undo_list->refcnt); + refcount_inc(&undo_list->refcnt); tsk->sysvsem.undo_list = undo_list; } else tsk->sysvsem.undo_list = NULL; @@ -2070,7 +2070,7 @@ void exit_sem(struct task_struct *tsk) return; tsk->sysvsem.undo_list = NULL; - if (!atomic_dec_and_test(&ulp->refcnt)) + if (!refcount_dec_and_test(&ulp->refcnt)) return; for (;;) { |