* [PATCH] usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN
@ 2022-03-24 23:02 Kees Cook
2022-03-25 5:31 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: Kees Cook @ 2022-03-24 23:02 UTC (permalink / raw)
To: Matthew Wilcox (Oracle)
Cc: Kees Cook, Christoph Hellwig, linux-kernel, linux-hardening
CONFIG_HARDENED_USERCOPY_PAGESPAN has been mostly broken for a while,
and it has become hard to ignore with some recent scsi changes[1].
While there is a more complete series to replace it with better checks[2],
it should have more soak time in -next. Instead, disable the config now,
with the expectation that it will be fully replaced in the next kernel
release.
[1] https://lore.kernel.org/lkml/20220324064846.GA12961@lst.de/
[2] https://lore.kernel.org/linux-hardening/20220110231530.665970-1-willy@infradead.org/
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
security/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/Kconfig b/security/Kconfig
index 0b847f435beb..88a0bc8c592b 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -166,7 +166,7 @@ config HARDENED_USERCOPY
config HARDENED_USERCOPY_PAGESPAN
bool "Refuse to copy allocations that span multiple pages"
depends on HARDENED_USERCOPY
- depends on EXPERT
+ depends on BROKEN
help
When a multi-page allocation is done without __GFP_COMP,
hardened usercopy will reject attempts to copy it. There are,
--
2.32.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN
2022-03-24 23:02 [PATCH] usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN Kees Cook
@ 2022-03-25 5:31 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2022-03-25 5:31 UTC (permalink / raw)
To: Kees Cook
Cc: Matthew Wilcox (Oracle),
Christoph Hellwig, linux-kernel, linux-hardening
On Thu, Mar 24, 2022 at 04:02:55PM -0700, Kees Cook wrote:
> CONFIG_HARDENED_USERCOPY_PAGESPAN has been mostly broken for a while,
> and it has become hard to ignore with some recent scsi changes[1].
> While there is a more complete series to replace it with better checks[2],
> it should have more soak time in -next. Instead, disable the config now,
> with the expectation that it will be fully replaced in the next kernel
> release.
>
> [1] https://lore.kernel.org/lkml/20220324064846.GA12961@lst.de/
> [2] https://lore.kernel.org/linux-hardening/20220110231530.665970-1-willy@infradead.org/
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> Signed-off-by: Kees Cook <keescook@chromium.org>
I'd prefer to just remove the code, but this is better than nothing:
Acked-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-03-24 23:02 [PATCH] usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN Kees Cook
2022-03-25 5:31 ` Christoph Hellwig
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