Hi, On Wed, Aug 03, 2022 at 03:28:19PM -0400, Paul Moore wrote: > On Wed, Aug 3, 2022 at 9:16 AM Paul Moore <paul@xxxxxxxxxxxxxx> wrote: > > On Wed, Aug 3, 2022 at 1:03 AM Peilin Ye <yepeilin.cs@xxxxxxxxx> wrote: > > > Hi all, > > > > > > A better way to fix this memleak would probably be checking > > > @args->io_thread in copy_process()? Something like: > > > > > > if (args->io_thread) > > > retval = audit_alloc_kernel(); > > > else > > > retval = audit_alloc(); > > > > > > But I didn't want to add another if to copy_process() for this bugfix. > > > Please suggest, thanks! > > > > Thanks for the report and patch! I'll take a closer look at this > > today and get back to you. > > I think the best solution to this is simply to remove the calls to > audit_alloc_kernel() in the io_uring and io-wq code, as well as the > audit_alloc_kernel() function itself. As long as create_io_thread() > ends up calling copy_process to create the new kernel thread the > audit_context should be allocated correctly. Peilin Ye, are you able > to draft a patch to do that and give it a test? Sure, I will write a v2 today. Thanks for the suggestion! > For those that may be wondering how this happened (I definitely was!), > it looks like when I first started working on the LSM/audit support > for io_uring it was before the v5.12-rc1 release when > create_io_thread() was introduced. Prior to create_io_thread() it > appears that io_uring/io-wq wasn't calling into copy_process() and > thus was not getting an audit_context allocated in the kernel thread's > task_struct; the solution for those original development drafts was to > add a call to a new audit_alloc_kernel() which would handle the > audit_context allocation. Unfortunately, I didn't notice the move to > create_io_thread() during development and the redundant > audit_alloc_kernel() calls remained :/ Thanks, Peilin Ye
