[tip: x86/urgent] x86/Kconfig: only enable ROX cache in execmem when STRICT_MODULE_RWX is set

[tip-bot2 for Mike Rapoport (Microsoft)]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     47410d839fcda6890cb82828f874f97710982f24
Gitweb:        https://git.kernel.org/tip/47410d839fcda6890cb82828f874f97710982f24
Author:        Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
AuthorDate:    Tue, 03 Jun 2025 14:14:42 +03:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 11 Jun 2025 11:20:51 +02:00

x86/Kconfig: only enable ROX cache in execmem when STRICT_MODULE_RWX is set

Currently ROX cache in execmem is enabled regardless of
STRICT_MODULE_RWX setting. This breaks an assumption that module memory
is writable when STRICT_MODULE_RWX is disabled, for instance for kernel
debuggin.

Only enable ROX cache in execmem when STRICT_MODULE_RWX is set to
restore the original behaviour of module text permissions.

Fixes: 64f6a4e10c05 ("x86: re-enable EXECMEM_ROX support")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20250603111446.2609381-3-rppt@xxxxxxxxxx
---
 arch/x86/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 340e546..71019b3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -89,7 +89,7 @@ config X86
 	select ARCH_HAS_DMA_OPS			if GART_IOMMU || XEN
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
 	select ARCH_HAS_ELF_RANDOMIZE
-	select ARCH_HAS_EXECMEM_ROX		if X86_64
+	select ARCH_HAS_EXECMEM_ROX		if X86_64 && STRICT_MODULE_RWX
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL