After tar_close() libtar.c releases the memory pointed to by pointer t. After tar_close() is called in the list() function it continues to use pointer t: free_longlink_longname(t->th_buf) . As a result the released memory is used (use-after-free).

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CVE-2021-33640

After tarclose, libtar.c releases the memory pointed to by pointer t. After tarclose is called in the list function, it continues to use pointer t: freelonglinklongnamet-thbuf . As a result, the released memory is used use-after-free...