062f40ef3e
rejecting invalid values for n is fine even in the case where a new sem will not be created, since the kernel does its range checks on n even in this case as well. by default, the kernel will bound the limit well below USHRT_MAX anyway, but it's presumably possible that an administrator could override this limit and break things.
19 lines
520 B
C
19 lines
520 B
C
#include <sys/sem.h>
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#include <limits.h>
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#include <errno.h>
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#include "syscall.h"
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#include "ipc.h"
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int semget(key_t key, int n, int fl)
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{
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/* The kernel uses the wrong type for the sem_nsems member
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* of struct semid_ds, and thus might not check that the
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* n fits in the correct (per POSIX) userspace type, so
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* we have to check here. */
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if (n > USHRT_MAX) return __syscall_ret(-EINVAL);
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#ifdef SYS_semget
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return syscall(SYS_semget, key, n, fl);
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#else
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return syscall(SYS_ipc, IPCOP_semget, key, n, fl);
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#endif
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}
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