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/[email protected] Signed-off-by: Elena Reshetova <[email protected]> Signed-off-by: Hans Liljestrand <[email protected]> Signed-off-by: Kees Cook <[email protected]> Signed-off-by: David Windsor <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Serge Hallyn <[email protected]> Cc: <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Manfred Spraul <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/linux/ipc.h b/include/linux/ipc.h index fadd579..ae68980 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 */