2022-03-25 19:53:56

by Kees Cook

[permalink] [raw]
Subject: [PATCH] usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN

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/[email protected]/
[2] https://lore.kernel.org/linux-hardening/[email protected]/

Suggested-by: Christoph Hellwig <[email protected]>
Cc: "Matthew Wilcox (Oracle)" <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
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