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.
Fixes:
5586cf61e108 ("powerpc: introduce execute-only pkey")
Cc: stable@vger.kernel.org # v4.16+
Reported-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
{
/*
* 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;
/*