Disassociate the exec_key from a VMA if the VMA permission is not
PROT_EXEC anymore. Otherwise the exec_only key continues to be
associated with the vma, causing unexpected behavior.
The problem was reported on x86 by Shakeel Butt,
which is also applicable on powerpc.
cc: Shakeel Butt <shake...@google.com>
Reported-by: Shakeel Butt <shake...@google.com>
Fixes 5586cf6 ("powerpc: introduce execute-only pkey")
Signed-off-by: Ram Pai <linux...@us.ibm.com>
---
arch/powerpc/mm/pkeys.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index e81d59e..fdeb9f5 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -425,9 +425,9 @@ int __arch_override_mprotect_pkey(struct vm_area_struct
*vma, int prot,
{
/*
* If the currently associated pkey is execute-only, but the requested
- * protection requires read or write, move it back to the default pkey.
+ * protection is not execute-only, move it back to the default pkey.
*/
- if (vma_is_pkey_exec_only(vma) && (prot & (PROT_READ | PROT_WRITE)))
+ if (vma_is_pkey_exec_only(vma) && (prot != PROT_EXEC))
return 0;
/*
--
1.7.1
