Commit 40998521 authored Nov 28, 2018 by Christophe Leroy Committed by Greg Kroah-Hartman Feb 12, 2019

powerpc/mm: Fix reporting of kernel execute faults on the 8xx



[ Upstream commit ffca395b11c4a5a6df6d6345f794b0e3d578e2d0 ]

On the 8xx, no-execute is set via PPP bits in the PTE. Therefore
a no-exec fault generates DSISR_PROTFAULT error bits,
not DSISR_NOEXEC_OR_G.

This patch adds DSISR_PROTFAULT in the test mask.

Fixes: d3ca5874 ("powerpc/mm: Fix reporting of kernel execute faults")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 4ab6a031

arch/powerpc/mm/fault.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -215,7 +215,9 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
		static bool bad_kernel_fault(bool is_exec, unsigned long error_code,
		unsigned long address)
		{
		if (is_exec && (error_code & (DSISR_NOEXEC_OR_G \| DSISR_KEYFAULT))) {
		/* NX faults set DSISR_PROTFAULT on the 8xx, DSISR_NOEXEC_OR_G on others */
		if (is_exec && (error_code & (DSISR_NOEXEC_OR_G \| DSISR_KEYFAULT \|
		DSISR_PROTFAULT))) {
		printk_ratelimited(KERN_CRIT "kernel tried to execute"
		" exec-protected page (%lx) -"
		"exploit attempt? (uid: %d)\n",