Re: [PATCH] x86/sgx: fix a NULL pointer

From: Haitao Huang
Date: Wed Jul 19 2023 - 09:53:27 EST


Hi Dave and Kai
On Tue, 18 Jul 2023 19:21:54 -0500, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:

On 7/18/23 17:14, Huang, Kai wrote:
Also perhaps the patch title is too vague. Adding more information doesn't hurt
I think, e.g., mentioning it is a fix for NULL pointer dereference in the EAUG
flow.

Yeah, let's say something like:

x86/sgx: Resolve SECS reclaim vs. page fault race

The patch is not to resolve SECS vs #PF race though the race is a necessary condition to cause the NULL pointer. The same condition does not cause NULL pointer in the ELDU path of #PF, only in EAUG path of #PF.

And the issue really is the NULL pointer not checked and fix was to reuse the same code to reload SECS in ELDU code path for EAUG code path


How about this:

x86/sgx: Reload reclaimed SECS for EAUG on #PF

or

x86/sgx: Fix a NULL pointer to SECS used for EAUG on #PF

BR
Haitao