hi
I accidentally copied a section of JSON text to the terminal and executed it,
which resulted in a system crash.Bash version is 5.1.8.
Later, I reproduced it and found that when I executed the following command,
the memory usage of bash became very large.
$
[{"key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1"},{"key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1"},{"key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1"},{"key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1","key":"1"}]
Through tracking the code, it was found that in the brace_expand_word_list
function, there is a continuous recursive execution of the brace_expand
function, which causes the len2 variable of function array_concat to become
abnormally large, and then a large amount of memory will be malloced based on
the value of len2
This may be a normal manifestation of bash rather than a problem. But in the
case of user misoperation, it can cause system crashes, so I still hope that
this situation can be improved
