Testing procedure:
https://wiki.mageia.org/en/QA_procedure:Libxml2

Also note the PoC linked in Comment 0.

Whiteboard: (none) => has_procedure

Tested the general procedure on Mageia 5 i586, verified OK.

Confirmed the infinite loop in the PoC before the update.  After the update it errors out with:
$ xmllint test.xz
test.xz:1: parser error : Document is empty

^
test.xz:1: parser error : Start tag expected, '<' not found

^

Whiteboard: has_procedure => has_procedure MGA5-32-OK

Trying this on x86_64.

First tried reproducing the PoC before the update.
$ gdb --quiet --args xmllint test.xz
Reading symbols from xmllint...Reading symbols from /home/lcl/Downloads/xmllint...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Missing separate debuginfos, use: debuginfo-install libxml2-utils-2.9.1-11.2.mga5.x86_64
(gdb) q

So forget that...
$ xmllint test.xz
^C
It hangs there forever until a Ctrl-C.
strace produces several lines of output before the hang.
It shows that the test file is opened and a couple of read operations performed and then nothing.

stat("test.xz", {st_mode=S_IFREG|0644, st_size=28, ...}) = 0
stat("test.xz", {st_mode=S_IFREG|0644, st_size=28, ...}) = 0
stat("test.xz", {st_mode=S_IFREG|0644, st_size=28, ...}) = 0
open("test.xz", O_RDONLY)               = 3
lseek(3, 0, SEEK_CUR)                   = 0
getcwd("/home/lcl/Downloads", 1024)     = 20
read(3, "\v\0\2\0\0\0\0\0\0@\0\0\0\0\20\20\20\20\20\20\20\20\0\0\377\377\0\0", 8192) = 28
read(3, "", 8164)                       = 0

Presumably this is a successful PoC.

CC: (none) => tarazed25

After the update:
$ xmllint test.xz
test.xz:1: parser error : Document is empty

^
test.xz:1: parser error : Start tag expected, '<' not found

^

Created the files indicated in the testing procedure and ran the preliminary tests:

[lcl@vega ~]$ python testxml.py
Tested OK
[lcl@vega ~]$ xmllint --auto
<?xml version="1.0"?>
<info>abc</info>
[lcl@vega ~]$ xmlcatalog --create
<?xml version="1.0"?>
<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd">
<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/>

[lcl@vega ~]$ sudo urpmi chromium-browser

The chromium-browser test seemed to come a bit unstuck:

[lcl@vega ~]$ strace -o strace.out chromium-browser
[2879:2879:1104/142117:ERROR:whitelist.cc(61)] Component extension with id nmmhkkegccagdldgiimedpiccmgmieda not in whitelist and is not being loaded as a result.
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
[2879:2879:1104/142122:ERROR:navigation_entry_screenshot_manager.cc(141)] Invalid entry with unique id: 1
[lcl@vega ~]$ grep xml strace.out
open("/usr/lib64/chromium-browser/libxml2.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("tls/x86_64/libxml2.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("tls/libxml2.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("x86_64/libxml2.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("libxml2.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/lib64/libxml2.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib64/libxml2.so.2.9.1", O_RDONLY) = 3
read(14, "<?xml version=\"1.0\"?>\n<!DOCTYPE "..., 8192) = 5553

then a succession of read messages.

libpng warnings often crop up and can probably be ignored but I am puzzled by the missing files messages.  The output differs from what is expected.

Len, your tests look fine.

An update for this issue has been pushed to Mageia Updates repository.

http://advisories.mageia.org/MGASA-2015-0433.html

Status: NEW => RESOLVED
Resolution: (none) => FIXED