From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
ruscur@russell.cc
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v1 1/6] powerpc/mm: Fix reporting of kernel execute faults on the 8xx
Date: Wed, 7 Nov 2018 16:56:27 +0000 (UTC) [thread overview]
Message-ID: <ab8fcb458e1a6ad86382767b3ce7f7cc0d5b7121.1541568127.git.christophe.leroy@c-s.fr> (raw)
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>
---
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 1697e903bbf2..50e5c790d11e 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -226,7 +226,9 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr,
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",
--
2.13.3
next reply other threads:[~2018-11-07 16:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 16:56 Christophe Leroy [this message]
2018-11-07 16:56 ` [RFC PATCH v1 2/6] powerpc: Add framework for Kernel Userspace Protection Christophe Leroy
2018-11-07 16:56 ` [RFC PATCH v1 3/6] powerpc: Add skeleton for Kernel Userspace Execution Prevention Christophe Leroy
2018-11-19 2:44 ` Russell Currey
2018-11-21 11:50 ` Michael Ellerman
2018-11-07 16:56 ` [RFC PATCH v1 4/6] powerpc/8xx: Add " Christophe Leroy
2018-11-07 16:56 ` [RFC PATCH v1 5/6] powerpc/mm: Add a framework for Kernel Userspace Access Protection Christophe Leroy
2018-11-07 17:08 ` Christophe LEROY
2018-11-21 2:26 ` Russell Currey
2018-11-21 8:32 ` Christophe LEROY
2018-11-22 1:25 ` Russell Currey
2018-11-28 10:05 ` Christophe LEROY
2018-11-07 16:56 ` [RFC PATCH v1 6/6] powerpc/8xx: Add " Christophe Leroy
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