Messages in this thread | | | Date | Tue, 31 Oct 2023 00:58:54 -0400 | From | Gregory Price <> | Subject | Re: [PATCH] base/node.c: initialize the accessor list before registering |
| |
On Tue, Oct 31, 2023 at 07:03:17AM +0100, Greg KH wrote: > On Mon, Oct 30, 2023 at 12:42:39AM -0400, Gregory Price wrote: > > The current code registers the node as available in the node array > > before initializing the accessor list. This makes it so that > > anything which might access the accessor list as a result of > > allocations will cause an undefined memory access. > > > > In one example, an extension to access hmat data during interleave > > caused this undefined access as a result of a bulk allocation > > that occurs during node initialization but before the accessor > > list is initialized. > > Is this an in-kernel driver that causes this problem? >
I discovered this why testing an RFC: https://lore.kernel.org/linux-mm/ZUCCoCRS3cohf9OE@memverge.com/T/#t
However I noticed that there are two exposed interfaces which may allow a caller to hit the unitialized accessor list. I haven't explicitly demonstrated this, though.
1) register_memory_node_under_compute_node 2) node_set_perf_attrs
Since `register_node` calls into device_register and inevitably hits allocators, it seems like fully initializing the node struct before going off into the aether was appropriate.
> > > > Initialize the accessor list before making the node generally > > available to the global system. > > > > Signed-off-by: Gregory Price <gregory.price@memverge.com> > > What commit id does this fix? >
Sorry: Fixes: 08d9dbe72b1f ("node: Link memory nodes to their compute nodes")
> thanks, > > greg k-h
| |