Is it possible to overwrite the file /proc/sys/dev/cdrom/info?

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux

Issue

  • Is it possible to overwrite the file /proc/sys/dev/cdrom/info?

Resolution

From source, it is seen that .mode is set as 0444.

                 .ctl_name       = DEV_CDROM_INFO,
                 .procname       = "info",
                 .data           = &cdrom_sysctl_settings.info,
                 .maxlen         = CDROM_STR_SIZE,
                 .mode           = 0444,
                 .proc_handler   = &cdrom_sysctl_info,

This means that the file does not have write permissions unlike other files in the same directory.

# ll /proc/sys/dev/cdrom/
total 0
-rw-r--r-- 1 root root 0 Sep 13 06:29 autoclose
-rw-r--r-- 1 root root 0 Sep 13 06:29 autoeject
-rw-r--r-- 1 root root 0 Sep 13 06:29 check_media
-rw-r--r-- 1 root root 0 Sep 13 06:29 debug
-r--r--r-- 1 root root 0 Sep 13 06:29 info <-------------
-rw-r--r-- 1 root root 0 Sep 13 06:29 lock

So it is not possible to write or overwrite the file.

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