samba-bugs at samba.org
2017-Oct-27 03:54 UTC
[Bug 13105] New: 1byte heap overflow in sanitize_path
https://bugzilla.samba.org/show_bug.cgi?id=13105
Bug ID: 13105
Summary: 1byte heap overflow in sanitize_path
Product: rsync
Version: 3.1.3
Hardware: All
OS: All
Status: NEW
Severity: normal
Priority: P5
Component: core
Assignee: wayned at samba.org
Reporter: jeriko.one at gmx.us
QA Contact: rsync-qa at samba.org
Created attachment 13733
--> https://bugzilla.samba.org/attachment.cgi?id=13733&action=edit
Use MAX to ensure at least 2 bytes are allocated for dest
$ ./rsync --version
rsync version 3.1.3dev protocol version 31
The path that'll hit this issue is when using rsyncd and you receive
arguments
from the client like:
"--server" "--sender" "." " test/"
Where "test" is the name of a module.
sanitize_path doesn't handle the case where the argument p is ==
"\0" and p !dest
This leads to a 1 byte overwrite as the allocation of dest is too small.
sanitize_path (dest=0x0, p=0x60200000ebb0 "",
rootdir=0x4f51e0 "", depth=0, flags=1) at util.c:1009
1011 if (dest != p) {
1012 int plen = strlen(p); <-- returns 0
1023 } else if (!(dest = new_array(char, rlen + plen + 1))) <-- 1
byte
requested
1037 start = sanp = dest + rlen;
1073 if (sanp == dest) {
1074 /* ended up with nothing, so put in "." component */
1075 *sanp++ = '.';
1076 }
1077 *sanp = '\0'; <-- overwrite by 1
The patch I've attached will ensures that at least 2 bytes are allocated for
dest.
Below is the ASan output
==================================================================24556==ERROR:
AddressSanitizer: heap-buffer-overflow on address
0x60200000eb71 at pc 0x00000044b486 bp 0x7fffffffabd0 sp 0x7fffffffabc0
WRITE of size 1 at 0x60200000eb71 thread T0
#0 0x44b485 in sanitize_path /home/raj/rsync/rsync/util.c:1077
#1 0x449484 in glob_expand /home/raj/rsync/rsync/util.c:717
#2 0x449af8 in glob_expand_module /home/raj/rsync/rsync/util.c:783
#3 0x478b61 in read_args /home/raj/rsync/rsync/io.c:1266
#4 0x4b12b6 in rsync_module /home/raj/rsync/rsync/clientserver.c:869
#5 0x4b2a49 in start_daemon /home/raj/rsync/rsync/clientserver.c:1135
#6 0x48f56e in start_accept_loop /home/raj/rsync/rsync/socket.c:618
#7 0x4b320a in daemon_main /home/raj/rsync/rsync/clientserver.c:1237
#8 0x4582da in main /home/raj/rsync/rsync/main.c:1627
#9 0x7ffff64d866f in __libc_start_main (/lib64/libc.so.6+0x2066f)
#10 0x4047c8 in _start (/home/raj/rsync/asan/bin/rsync+0x4047c8)
0x60200000eb71 is located 0 bytes to the right of 1-byte region
[0x60200000eb70,0x60200000eb71)
allocated by thread T0 here:
#0 0x7ffff6f04572 in malloc
(/usr/lib/gcc/x86_64-pc-linux-gnu/5.4.0/libasan.so.2+0x98572)
#1 0x44e480 in _new_array /home/raj/rsync/rsync/util2.c:68
#2 0x44aed9 in sanitize_path /home/raj/rsync/rsync/util.c:1023
#3 0x449484 in glob_expand /home/raj/rsync/rsync/util.c:717
#4 0x449af8 in glob_expand_module /home/raj/rsync/rsync/util.c:783
#5 0x478b61 in read_args /home/raj/rsync/rsync/io.c:1266
#6 0x4b12b6 in rsync_module /home/raj/rsync/rsync/clientserver.c:869
#7 0x4b2a49 in start_daemon /home/raj/rsync/rsync/clientserver.c:1135
#8 0x48f56e in start_accept_loop /home/raj/rsync/rsync/socket.c:618
#9 0x4b320a in daemon_main /home/raj/rsync/rsync/clientserver.c:1237
#10 0x4582da in main /home/raj/rsync/rsync/main.c:1627
#11 0x7ffff64d866f in __libc_start_main (/lib64/libc.so.6+0x2066f)
SUMMARY: AddressSanitizer: heap-buffer-overflow
/home/raj/rsync/rsync/util.c:1077 sanitize_path
Shadow bytes around the buggy address:
0x0c047fff9d10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9d20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9d30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9d40: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c047fff9d50: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9d60: fa fa fa fa fa fa fa fa fa fa fa fa fa fa[01]fa
0x0c047fff9d70: fa fa 07 fa fa fa 07 fa fa fa fd fa fa fa 02 fa
0x0c047fff9d80: fa fa 00 01 fa fa 00 01 fa fa 00 07 fa fa fd fd
0x0c047fff9d90: fa fa fd fd fa fa fd fa fa fa 00 00 fa fa 00 00
0x0c047fff9da0: fa fa 00 00 fa fa 05 fa fa fa 05 fa fa fa 07 fa
0x0c047fff9db0: fa fa fd fd fa fa 00 04 fa fa fd fd fa fa fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
==24556==ABORTING
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samba-bugs at samba.org
2017-Oct-29 22:57 UTC
[Bug 13105] 1byte heap overflow in sanitize_path
https://bugzilla.samba.org/show_bug.cgi?id=13105
Wayne Davison <wayned at samba.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #1 from Wayne Davison <wayned at samba.org> ---
I committed a fix to git. Thanks!
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