Bug 1484276

Summary: There is an illegal address access in alloc_entry.c of libncurses.
Product: Red Hat Enterprise Linux 7 Reporter: owl337 <v.owl337>
Component: ncursesAssignee: Miroslav Lichvar <mlichvar>
Status: CLOSED DUPLICATE QA Contact: qe-baseos-daemons
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.5-AltCC: akhaitov, dickey
Target Milestone: rc   
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Hardware: Unspecified   
OS: Unspecified   
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Last Closed: 2018-07-27 15:24:06 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Blocks: 1488916    
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Description Flags
Triggered by " ./tic POC8 " none

Description owl337 2017-08-23 07:47:37 UTC 
Created attachment 1316976 [details]
Triggered by " ./tic POC8 "

Description of problem:

There is an illegal address access in alloc_entry.c of libncurses.

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

<= latest version

How reproducible:

 ./tic POC8

Steps to Reproduce:


$ ./tic POC8
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 10, terminal 'l': Missing separator after `rs', have c
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 13, terminal 'l': Illegal character - '^J'
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 13, terminal 'l': wrong type used for string capability 'll'
Segmentation fault


The GDB debugging information is as follows:
(gdb) r 
...
Breakpoint 1, _nc_save_str (string=0x67c690 "l") at ../ncurses/./tinfo/alloc_entry.c:103
103	    len = strlen(string) + 1;
(gdb) n
105	    if (len == 1 && next_free != 0) {
(gdb) c
Continuing.
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 10, terminal 'l': Missing separator after `rs', have c
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 13, terminal 'l': Illegal character - '^J'
"id:000018,sig:11,src:000518,op:arith8,pos:6,val:+3", line 1, col 13, terminal 'l': wrong type used for string capability 'll'

Breakpoint 1, _nc_save_str (string=0xffffffffffffffff <error: Cannot access memory at address 0xffffffffffffffff>)
    at ../ncurses/./tinfo/alloc_entry.c:103
103	    len = strlen(string) + 1;
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
strlen () at ../sysdeps/x86_64/strlen.S:137
137	../sysdeps/x86_64/strlen.S: No such file or directory.
(gdb) bt
#0  strlen () at ../sysdeps/x86_64/strlen.S:137
#1  0x0000000000453602 in _nc_save_str (
    string=0xffffffffffffffff <error: Cannot access memory at address 0xffffffffffffffff>)
    at ../ncurses/./tinfo/alloc_entry.c:103
#2  0x0000000000445566 in postprocess_termcap (tp=<optimized out>, has_base=<optimized out>)
    at ../ncurses/./tinfo/parse_entry.c:679
#3  _nc_parse_entry (entryp=0x7fffffffaf28, literal=<optimized out>, silent=<optimized out>)
    at ../ncurses/./tinfo/parse_entry.c:520
#4  0x000000000043db23 in _nc_read_entry_source (fp=<optimized out>, buf=<optimized out>, literal=0, silent=false, 
    hook=0x40e230 <immedhook>) at ../ncurses/./tinfo/comp_parse.c:225
#5  0x0000000000403039 in main (argc=<optimized out>, argv=<optimized out>) at ../progs/tic.c:958
(gdb) 

Trigged in:
_nc_save_str (string=0xffffffffffffffff <error: Cannot access memory at address 0xffffffffffffffff>)
    at ../ncurses/./tinfo/alloc_entry.c:103
103	    len = strlen(string) + 1;

Actual results:

crash

Expected results:

crash

Additional info:

Credits:

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.
Comment 2 Thomas E. Dickey 2017-08-26 00:37:16 UTC 
I made a fix for this report which will be in the next set of updates.