On Fri, Apr 11, 2014 at 10:53:21PM -0400, Wang, Xiaoming wrote: > This is a typical refcount leak exploitable by unprivileged users. > Current group_info had been got in ping_init_sock and > group_info->usage increased. But the usage hasn't decreased > anywhere in ping. This will make this group_info never freed. >
The patch is fine, however I had a brainfart with my last sentence about commit message, sorry for that. group_info *can be freed* by malicious user while still being pointed to by something, that's the biggest problem with refcount leaks, therefore this message needs some reworking. I think that discussion about various consequences of refcount leak in commit message is not necessary. how about: Plug a group_info refcount leak in ping_init. group_info is only needed during initialization and the code failed to release the reference on exit. While here move grabbing the reference to a place where it is actually needed. ==== Please cc: me if you resend the patch. Thanks, -- Mateusz Guzik -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
