[PATCH v2 22/37] powerpc: Fail ioremap() instead of silently ignoring flags when PAGE_USER is set
From: Christophe Leroy <hidden>
Date: 2023-09-25 18:34:19
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Calling ioremap() with _PAGE_USER (or _PAGE_PRIVILEDGE unset) is wrong. Loudly fail the call to ioremap() instead of blindly clearing the flags. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/mm/ioremap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/ioremap.c b/arch/powerpc/mm/ioremap.c
index d5159f205380..7823c38f09de 100644
--- a/arch/powerpc/mm/ioremap.c
+++ b/arch/powerpc/mm/ioremap.c@@ -51,7 +51,8 @@ void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long flags) pte = pte_mkdirty(pte); /* we don't want to let _PAGE_USER leak out */ - pte = pte_mkprivileged(pte); + if (WARN_ON(pte_user(pte))) + return NULL; if (iowa_is_active()) return iowa_ioremap(addr, size, pte_pgprot(pte), caller);
--
2.41.0