Messages in this thread | | | Date | Tue, 12 May 2015 15:24:19 +0800 | From | Minfei Huang <> | Subject | Re: [PATCH] livepatch: Prevent to enable uninitialized patch |
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On 05/12/15 at 12:49P, Jiri Kosina wrote: > On Mon, 11 May 2015, Minfei Huang wrote: > > > 1) Patched a patch to fix the issue for module A. > > 2) livepatch will try to enable the patch, while the corresponding > > module is loaded ( call klp_module_notify_coming ) > > 3) Firstly, livepatch will do the instruction "obj->mod = mod", whatever > > the result of klp_module_notify_coming is. > > 4) livepatch may fail to call the klp_init_object_loaded or > > klp_enable_object > > 5) klp_module_notify_coming returns > > > > 6) For the userspace, we can enable the patch again ( disable the patch > > firstly, then enable the patch from the sysfs ) > > 7) In order to enable the patch, livepatch will call __klp_enable_patch > > 8) we can pass the limitation (klp_is_object_loaded), because the value > > of obj->mod is not NULL ( the obj->mod obtains the value from the step 3 ) > > 9) the patch may be applied, although the patch is not initialized, if > > the value of func->old_addr is not NULL > > > > From the above description, we can see the uninitialized patch ( the > > patch should be initialized by the klp_init_object_loaded in general ) > > can be applied to the kernel. > > This indeed looks like a valid breakage scenario. > > Could you please resend v2 of this patch with much more detailed > description in the changelog? (i.e. some reformulated variation on the > text above). Your original submission didn't describe the problem your > patch is fixing at all. > > Thanks,
Thanks for your review. I will repost a new patch.
Thanks Minfei
> > -- > Jiri Kosina > SUSE Labs
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