Você pulou a parte importante antes do comando dd, da documentação do kernel :
For example, the following code will generate an error for any write access at socket 0, on any DIMM/address on channel 2:
echo 2 >/sys/devices/system/edac/mc/mc0/inject_addrmatch/channel echo 2 >/sys/devices/system/edac/mc/mc0/inject_type echo 64 >/sys/devices/system/edac/mc/mc0/inject_eccmask echo 3 >/sys/devices/system/edac/mc/mc0/inject_section echo 1 >/sys/devices/system/edac/mc/mc0/inject_enable dd if=/dev/mem of=/dev/null seek=16k bs=4k count=1 >& /dev/null
O driver do kernel gera erros, isso não tem nada a ver com o dd, o dd é usado apenas para ativá-lo.