Re: [PATCH] RDMA/restrack: Fix potential invalid address access

[Leon Romanovsky <leon@kernel.org>]

On Mon, Mar 04, 2024 at 11:21:19AM +0800, Wenchao Hao wrote:
> On 2024/3/3 20:57, Leon Romanovsky wrote:
> > On Fri, Mar 01, 2024 at 05:55:15PM +0800, Wenchao Hao wrote:
> > > struct rdma_restrack_entry's kern_name was set to KBUILD_MODNAME
> > > in ib_create_cq(), while if the module exited but forgot del this
> > > rdma_restrack_entry, it would cause a invalid address access in
> > > rdma_restrack_clean() when print the owner of this rdma_restrack_entry.
> > 
> > How is it possible to exit owner module without cleaning the resources?
> > 
> 
> I meet this issue with one of our product who develop their owner kernel
> modules based on ib_core, and there are terrible logic with the exit
> code which cause resource leak.
> 
> Of curse it's bug of module who did not clear resource when exit, but
> I think ib_core should avoid accessing memory of other modules directly
> to provides better stability.
> 
> What's more, from the context of rdma_restrack_clean() when print
> "restack: %s %s object allocated by %s is not freed ...", it seems
> designed for the above scene where client has bug to alerts there
> are resource leak, so we should not panic on this log print.

Can you please share the kernel panic?

Thanks