| From c11f90f67127a810692fdbd6b3dc383bb72d822f Mon Sep 17 00:00:00 2001 |
| From: Christophe Leroy <christophe.leroy@c-s.fr> |
| Date: Wed, 28 Nov 2018 09:27:04 +0000 |
| Subject: 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: d3ca587404b3 ("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> |
| --- |
| arch/powerpc/mm/fault.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c |
| index 6e1e39035380..52863deed65d 100644 |
| --- a/arch/powerpc/mm/fault.c |
| +++ b/arch/powerpc/mm/fault.c |
| @@ -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", |
| -- |
| 2.19.1 |
| |
