Re: [PATCH] livepatch: Fix leak on klp_init_patch_early failure path
From: Josh Poimboeuf <hidden>
Date: 2021-12-14 03:13:18
Also in:
live-patching, lkml
From: Josh Poimboeuf <hidden>
Date: 2021-12-14 03:13:18
Also in:
live-patching, lkml
On Mon, Dec 13, 2021 at 02:58:38PM -0800, David Vernet wrote:
quoted
I don't think the fix will be quite that simple. For example, if klp_init_patch_early() fails, that means try_module_get() hasn't been done, so klp_free_patch_finish() will wrongly do a module_put().Ugh, good point and thank you for catching that. Another problem with the current patch is that we'll call kobject_put() on the patch even if we never call kobject_init on the patch due to patch->objs being NULL. Perhaps we should pull try_module_get() and the NULL check for patch->objs out of klp_init_patch_early()? It feels a bit more intuitive to me if klp_init_patch_early() were only be responsible for initializing kobjects for the patch and its objects / funcs anyways. Testing it locally seems to work fine. Let me know if this sounds reasonable to you, and I'll send out a v2 patch with the fixes to both the patch description, and logic.
Sounds reasonable to me. Thanks. -- Josh