Re: [RFC PATCH v2 0/9] Add LSM access controls and auditing to io_uring

On Wed, Aug 25, 2021 at 9:16 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > On 2021-08-24 16:57, Richard Guy Briggs wrote: > > On 2021-08-11 16:48, Paul Moore wrote: > > > Draft #2 of the patchset which brings auditing and proper LSM access > > > controls to the io_uring subsystem. The original patchset was posted > > > in late May and can be found via lore using the link below: > > > > > > https://lore.kernel.org/linux-security-module/162163367115.8379.845901263... > > > > > > This draft should incorporate all of the feedback from the original > > > posting as well as a few smaller things I noticed while playing > > > further with the code. The big change is of course the selective > > > auditing in the io_uring op servicing, but that has already been > > > discussed quite a bit in the original thread so I won't go into > > > detail here; the important part is that we found a way to move > > > forward and this draft captures that. For those of you looking to > > > play with these patches, they are based on Linus' v5.14-rc5 tag and > > > on my test system they boot and appear to function without problem; > > > they pass the selinux-testsuite and audit-testsuite and I have not > > > noticed any regressions in the normal use of the system. If you want > > > to get a copy of these patches straight from git you can use the > > > "working-io_uring" branch in the repo below: > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git > > > https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git > > > > > > Beyond the existing test suite tests mentioned above, I've cobbled > > > together some very basic, very crude tests to exercise some of the > > > things I care about from a LSM/audit perspective. These tests are > > > pretty awful (I'm not kidding), but they might be helpful for the > > > other LSM/audit developers who want to test things: > > > > > > https://drop.paul-moore.com/90.kUgq > > > > > > There are currently two tests: 'iouring.2' and 'iouring.3'; > > > 'iouring.1' was lost in a misguided and overzealous 'rm' command. > > > The first test is standalone and basically tests the SQPOLL > > > functionality while the second tests sharing io_urings across process > > > boundaries and the credential/personality sharing mechanism. The > > > console output of both tests isn't particularly useful, the more > > > interesting bits are in the audit and LSM specific logs. The > > > 'iouring.2' command requires no special arguments to run but the > > > 'iouring.3' test is split into a "server" and "client"; the server > > > should be run without argument: > > > > > > % ./iouring.3s > > > >>> server started, pid = 11678 > > > >>> memfd created, fd = 3 > > > >>> io_uring created; fd = 5, creds = 1 > > > > > > ... while the client should be run with two arguments: the first is > > > the PID of the server process, the second is the "memfd" fd number: > > > > > > % ./iouring.3c 11678 3 > > > >>> client started, server_pid = 11678 server_memfd = 3 > > > >>> io_urings = 5 (server) / 5 (client) > > > >>> io_uring ops using creds = 1 > > > >>> async op result: 36 > > > >>> async op result: 36 > > > >>> async op result: 36 > > > >>> async op result: 36 > > > >>> START file contents > > > What is this life if, full of care, > > > we have no time to stand and stare. > > > >>> END file contents > > > > > > The tests were hacked together from various sources online, > > > attribution and links to additional info can be found in the test > > > sources, but I expect these tests to die a fiery death in the not > > > to distant future as I work to add some proper tests to the SELinux > > > and audit test suites. > > > > > > As I believe these patches should spend a full -rcX cycle in > > > linux-next, my current plan is to continue to solicit feedback on > > > these patches while they undergo additional testing (next up is > > > verification of the audit filter code for io_uring). Assuming no > > > critical issues are found on the mailing lists or during testing, I > > > will post a proper patchset later with the idea of merging it into > > > selinux/next after the upcoming merge window closes. > > > > > > Any comments, feedback, etc. are welcome. > > > > Thanks for the tests. I have a bunch of userspace patches to add to the > > last set I posted and these tests will help exercise them. I also have > > one more kernel patch to post... I'll dive back into that now. I had > > wanted to post them before now but got distracted with AUDIT_TRIM > > breakage. > > Please tell me about liburing.h that is needed for these. There is one > in tools/io_uring/liburing.h but I don't think that one is right. > > The next obvious one would be include/uapi/linux/io_uring.h > > I must be missing something obvious here... You are looking for the liburing header files, the upstream is here: -> https://github.com/axboe/liburing If you are on a RH/IBM based distro it is likely called liburing[-devel]:

>> server started, pid = 2082 >> memfd created, fd = 3

% dnf whatprovides */liburing.h Last metadata expiration check: 0:38:37 ago on Wed 25 Aug 2021 08:54:22 PM EDT. liburing-devel-2.0-2.fc35.i686 : Development files for Linux-native io_uring I/O : access library Repo : rawhide Matched from: Filename : /usr/include/liburing.h liburing-devel-2.0-2.fc35.x86_64 : Development files for Linux-native io_uring : I/O access library Repo : @System Matched from: Filename : /usr/include/liburing.h liburing-devel-2.0-2.fc35.x86_64 : Development files for Linux-native io_uring : I/O access library Repo : rawhide Matched from: Filename : /usr/include/liburing.h -- paul moore