Created attachment 1293510 [details]
It is triggered by "./pspp-convert POC1 -O csv /dev/null"

Description of problem:
 There is a NULL Pointer Dereference in function ll_insert() of the libpspp library .

Version-Release number of selected component (if applicable):
 <= latest

How reproducible:

./pspp-convert POC1 -O csv /dev/null

Steps to Reproduce:

The information is as follows:

$./pspp-convert POC1 -O csv /dev/null
 
`POC1' near offset 0x1c0: Record type 7, subtype 18 has bad size 4 (expected 1).
Segmentation fault

The gdb debugging  information is as follows:

(gdb) s
ll_insert (new_elem=<optimized out>, before=<optimized out>) at ./src/libpspp/ll.h:448
448	  new_elem->next = before;
(gdb) i r $rax
rax            0x0	0
(gdb) x/3i $pc
=> 0x7ffff7a8ddfe <sfm_open+7358>:	mov    %r12,(%rax)
   0x7ffff7a8de01 <sfm_open+7361>:	mov    %rcx,0x8(%rax)
   0x7ffff7a8de05 <sfm_open+7365>:	mov    %rax,0x248(%r13)
(gdb) si

Program received signal SIGSEGV, Segmentation fault.
ll_insert (new_elem=<optimized out>, before=<optimized out>) at ./src/libpspp/ll.h:448
448	  new_elem->next = before;

The vulnerability was triggered in function ll_insert() at ll.h:448. In assembly mode we can see that register rax has accessed 0x0.

445 ll_insert (struct ll *before, struct ll *new_elem)
446 {
447   struct ll *before_prev = ll_prev (before);
448   new_elem->next = before;
449   new_elem->prev = before_prev;
450   before_prev->next = before->prev = new_elem;
451 }



Actual results:

crash

Expected results:

crash

Additional info:

This vulnerability is detected by team OWL337, with our custom fuzzer collAFL. Please contact ganshuitao  and chaoz.cn if you need more info about the team, the tool or the vulnerability.