Messages in this thread | | | From | "Edgecombe, Rick P" <> | Subject | Re: [PATCH] mm: Check writable zero page in page table check | Date | Tue, 6 Sep 2022 16:42:32 +0000 |
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On Mon, 2022-09-05 at 20:37 -0400, Pasha Tatashin wrote: > The idea behind page table check is to prevent some types of memory > corruptions: i.e. prevent false page sharing, and memory leaking > between address spaces. This is an optional security feature for > setups where it is more dangerous to leak data than to crash the > machine. Therefore, when page table check detects illegal page > sharing > it immediately crashes the kernel. I think we can have a > page_table_check option that would change BUG_ON to WARN_ON() (or to > WARN_ON_ONCE(), since once corruption is detected I believe it might > show up many times again)
Do you think there are a lot of people that would want to set page table check to BUG_ON mode, that wouldn't already be setting panic_on_warn?
I didn't realize page table check was meant to be a security feature as well. I thought it was more of a debug time checker.
Looking through more related discussions, there seems to be a strong aversion to "crash the kernel" features. Especially if they are meant to run in a non-testing context.
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