Date: Thu, 19 Apr 2012 19:20:45 -0700 From: "Eric W. Biederman" <ebiederm@...ssion.com> To: Eugene Teo <eugeneteo@...nel.sg>,Marcus Meissner <meissner@...e.de> CC: OSS Security List <oss-security@...ts.openwall.com>,security@...nel.org,Sukadev Bhattiprolu <sukadev@...ibm.com>,Serge Hallyn <serge.hallyn@...onical.com>,Pavel Emelyanov <xemul@...nvz.org> Subject: Re: CVE request: pid namespace leak in kernel 3.0 and 3.1 Eugene Teo <eugeneteo@...nel.sg> wrote: >On Fri, Apr 20, 2012 at 5:48 AM, Marcus Meissner <meissner@...e.de> >wrote: >> we had a user, Vadim Ponomarev (ccrssaa at karelia.ru), report a pid >> namespace leak caused by vsftpd. >> >> https://bugzilla.novell.com/show_bug.cgi?id=757783 >> >> He provided a simple reproducer: >[...] >> >> and checking "cat /proc/slabinfo|grep pid_namespace" >> gives 10000 more active slots after running it on 3.0.13 (+SUSE >patches) and 3.1.10 (+SUSE patches). >> >> Running this on 3.2.0 (+SUSE Patches) did not result in more slots, >so it was probably >> fixed between 3.1 and 3.2 (but someone else cross check perhaps). >> >> Any idea welcome on which patch fixed this, I tried >1b26c9b334044cff6d1d2698f2be41bc7d9a0864 >> but it seems not helping. > >I tested this with 3.0.25-rt44.57.el6rt.x86_64 yesterday, and I was >able to trigger the issue. The process needs to be privileged with >CAP_SYS_ADMIN. > >Eric, besides struct pid_namespace, there is a corresponding struct >pid_2 leak. Hmm. So we know what is holding the pid namespace reference. Additional thoughts. Does echo 3 > /proc/sys/vm/drop_caches clear up the issue? Is there a corresponding task_struct leak? Are the zombies getting reaped? I don't have much of a clue or much concern as this seems fixed in later kernels but I am happy to suggest things to look for to help narrow this down. Eric
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.