[PATCH] patch.bbclass: increase security

[PATCH] patch.bbclass: increase security

[Constantin Musca]

- Use mkdtemp for generating temp dir names
- Use bb.utils.remove for removing temp dirs
- Add comment for explaining the "patch" workaround

Signed-off-by: Constantin Musca <constantinx.musca@intel.com>
---
 meta/classes/patch.bbclass |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/meta/classes/patch.bbclass b/meta/classes/patch.bbclass
index d010438..4b535d9 100644
--- a/meta/classes/patch.bbclass
+++ b/meta/classes/patch.bbclass
@@ -139,10 +139,14 @@ python patch_do_patch() {
     path = os.getenv('PATH')
     os.putenv('PATH', d.getVar('PATH', True))
 
-    import shutil
-    process_tmpdir = os.path.join('/tmp', str(os.getpid()))
+    # We must use one TMPDIR per process (/tmp/${PID}${random_chars})
+    # so that the "patch" processes don't generate the same temp
+    # file name.
+
+    import tempfile
+    process_tmpdir = tempfile.mkdtemp(prefix=str(os.getpid()))
     if os.path.exists(process_tmpdir):
-        shutil.rmtree(process_tmpdir)
+        bb.utils.remove(process_tmpdir, True)
     os.makedirs(process_tmpdir)
     os.environ['TMPDIR'] = process_tmpdir
 
@@ -168,15 +172,15 @@ python patch_do_patch() {
         try:
             patchset.Import({"file":local, "strippath": parm['striplevel']}, True)
         except Exception as exc:
-            shutil.rmtree(process_tmpdir)
+            bb.utils.remove(process_tmpdir, True)
             bb.fatal(str(exc))
         try:
             resolver.Resolve()
         except bb.BBHandledException as e:
-            shutil.rmtree(process_tmpdir)
+            bb.utils.remove(process_tmpdir, True)
             bb.fatal(str(e))
 
-    shutil.rmtree(process_tmpdir)
+    bb.utils.remove(process_tmpdir, True)
 }
 patch_do_patch[vardepsexclude] = "PATCHRESOLVE"
 
-- 
1.7.9.5

Re: [PATCH] patch.bbclass: increase security

[Enrico Scholz]

Constantin Musca
<constantinx.musca-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:

> +    process_tmpdir = tempfile.mkdtemp(prefix=str(os.getpid()))

fwiw, prefix is usually something which identifies the origin of the
tempfile.  getpid() does not make much sense here; it might be better to
use something like 'bitbake-patch' or so.


>      if os.path.exists(process_tmpdir):

this will trigger everytime becuase 'mkdtemp()' creates the directory.

> +        bb.utils.remove(process_tmpdir, True)

this lowers the just gained security... :(


>      os.makedirs(process_tmpdir)

not needed


---> a plain

 |     process_tmpdir = tempfile.mkdtemp()
 |     os.environ['TMPDIR'] = process_tmpdir

suffices (add a custom prefix when you really want it).



Enrico
-- 
SIGMA Chemnitz GmbH       Registergericht:   Amtsgericht Chemnitz HRB 1750
Am Erlenwald 13           Geschaeftsfuehrer: Grit Freitag, Frank Pyritz
09128 Chemnitz

Re: [PATCH] patch.bbclass: increase security

[Constantin Musca]

On 09/14/2012 05:18 PM, Enrico Scholz wrote:
>
> Constantin Musca
> <constantinx.musca-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:
>
>> +    process_tmpdir = tempfile.mkdtemp(prefix=str(os.getpid()))
> fwiw, prefix is usually something which identifies the origin of the
> tempfile.  getpid() does not make much sense here; it might be better to
> use something like 'bitbake-patch' or so.
>
>
>>       if os.path.exists(process_tmpdir):
> this will trigger everytime becuase 'mkdtemp()' creates the directory.
>
>> +        bb.utils.remove(process_tmpdir, True)
> this lowers the just gained security... :(
>
>
>>       os.makedirs(process_tmpdir)
> not needed
>
>
> ---> a plain
>
>   |     process_tmpdir = tempfile.mkdtemp()
>   |     os.environ['TMPDIR'] = process_tmpdir
>
> suffices (add a custom prefix when you really want it).
>
>
>
> Enrico
Is it ok now ? ([PATCH v2] patch.bbclass: increase security)


Constantin