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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-09-08 16:17:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:51 -0700 |
| commit | 9405c03ee778cd3e353e55fff6e16dfdd9609c02 (patch) | |
| tree | 197d334b72ecc283c04b3fd80fbf2d5021acc249 | |
| parent | f74370b86ec1e0ee8a56ba838efe78e21d8dba23 (diff) | |
| download | linux-exynos-9405c03ee778cd3e353e55fff6e16dfdd9609c02.tar.gz linux-exynos-9405c03ee778cd3e353e55fff6e16dfdd9609c02.tar.bz2 linux-exynos-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>
| -rw-r--r-- | include/linux/ipc.h | 3 | ||||
| -rw-r--r-- | ipc/util.c | 6 |
2 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/ipc.h b/include/linux/ipc.h index fadd579d577d..ae68980e9d48 100644 --- a/include/linux/ipc.h +++ b/include/linux/ipc.h @@ -4,6 +4,7 @@ #include <linux/spinlock.h> #include <linux/uidgid.h> #include <uapi/linux/ipc.h> +#include <linux/refcount.h> #define IPCMNI 32768 /* <= MAX_INT limit for ipc arrays (including sysctl changes) */ @@ -22,7 +23,7 @@ struct kern_ipc_perm { void *security; struct rcu_head rcu; - atomic_t refcount; + refcount_t refcount; } ____cacheline_aligned_in_smp __randomize_layout; #endif /* _LINUX_IPC_H */ 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); |