NAME

       KEYCTL_UPDATE - update a key's data payload

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <linux/keyctl.h>  /* Definition of KEY* constants */
       #include <sys/syscall.h>   /* Definition of SYS_* constants */
       #include <unistd.h>

       long syscall(size_t size;
                    SYS_keyctl, KEYCTL_UPDATE, key_serial_t key,
                    void payload[size], size_t size);

DESCRIPTION

       Update a key's data payload.

       key  specifies  the ID of the key to be updated.  payload points to the new payload and size contains the
       new payload size in bytes.

       The caller must have write permission on the key specified and the key type must support updating.

       A negatively instantiated key (see  KEYCTL_REJECT(2const))  can  be  positively  instantiated  with  this
       operation.

RETURN VALUE

       On success, 0 is returned.

       On error, -1 is returned, and errno is set to indicate the error.

ERRORS

       The key type does not support updating.

VERSIONS

       A wrapper is provided in the libkeyutils library: keyctl_update(3).

STANDARDS

       Linux.

HISTORY

       Linux 2.6.10.

SEE ALSO

       keyctl(2), keyctl_update(3)

Linux man-pages 6.16                               2025-06-28                              KEYCTL_UPDATE(2const)