From: "Christopher M. Riedl" <cmr@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: tglx@linutronix.de, x86@kernel.org,
linux-hardening@vger.kernel.org, keescook@chromium.org,
npiggin@gmail.com, dja@axtens.net, peterz@infradead.org
Subject: [PATCH v5 4/8] lkdtm/x86_64: Add test to hijack a patch mapping
Date: Tue, 13 Jul 2021 00:31:09 -0500 [thread overview]
Message-ID: <20210713053113.4632-5-cmr@linux.ibm.com> (raw)
In-Reply-To: <20210713053113.4632-1-cmr@linux.ibm.com>
A previous commit implemented an LKDTM test on powerpc to exploit the
temporary mapping established when patching code with STRICT_KERNEL_RWX
enabled. Extend the test to work on x86_64 as well.
Signed-off-by: Christopher M. Riedl <cmr@linux.ibm.com>
---
drivers/misc/lkdtm/perms.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 39e7456852229..41e87e5f9cc86 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -224,7 +224,7 @@ void lkdtm_ACCESS_NULL(void)
}
#if (IS_BUILTIN(CONFIG_LKDTM) && defined(CONFIG_STRICT_KERNEL_RWX) && \
- defined(CONFIG_PPC))
+ (defined(CONFIG_PPC) || defined(CONFIG_X86_64)))
/*
* This is just a dummy location to patch-over.
*/
@@ -233,12 +233,25 @@ static void patching_target(void)
return;
}
-#include <asm/code-patching.h>
const u32 *patch_site = (const u32 *)&patching_target;
+#ifdef CONFIG_PPC
+#include <asm/code-patching.h>
+#endif
+
+#ifdef CONFIG_X86_64
+#include <asm/text-patching.h>
+#endif
+
static inline int lkdtm_do_patch(u32 data)
{
+#ifdef CONFIG_PPC
return patch_instruction((u32 *)patch_site, ppc_inst(data));
+#endif
+#ifdef CONFIG_X86_64
+ text_poke((void *)patch_site, &data, sizeof(u32));
+ return 0;
+#endif
}
static inline u32 lkdtm_read_patch_site(void)
@@ -249,11 +262,16 @@ static inline u32 lkdtm_read_patch_site(void)
/* Returns True if the write succeeds */
static inline bool lkdtm_try_write(u32 data, u32 *addr)
{
+#ifdef CONFIG_PPC
__put_kernel_nofault(addr, &data, u32, err);
return true;
err:
return false;
+#endif
+#ifdef CONFIG_X86_64
+ return !__put_user(data, addr);
+#endif
}
static int lkdtm_patching_cpu(void *data)
@@ -346,8 +364,8 @@ void lkdtm_HIJACK_PATCH(void)
void lkdtm_HIJACK_PATCH(void)
{
- if (!IS_ENABLED(CONFIG_PPC))
- pr_err("XFAIL: this test only runs on powerpc\n");
+ if (!IS_ENABLED(CONFIG_PPC) && !IS_ENABLED(CONFIG_X86_64))
+ pr_err("XFAIL: this test only runs on powerpc and x86_64\n");
if (!IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
pr_err("XFAIL: this test requires CONFIG_STRICT_KERNEL_RWX\n");
if (!IS_BUILTIN(CONFIG_LKDTM))
--
2.26.1
next prev parent reply other threads:[~2021-07-13 5:31 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 5:31 [PATCH v5 0/8] Use per-CPU temporary mappings for patching on Radix MMU Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 1/8] powerpc: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 2/8] lkdtm/powerpc: Add test to hijack a patch mapping Christopher M. Riedl
2021-08-05 9:13 ` Christophe Leroy
2021-08-11 17:57 ` Christopher M. Riedl
2021-08-11 18:07 ` Kees Cook
2021-07-13 5:31 ` [PATCH v5 3/8] x86_64: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-07-13 5:31 ` Christopher M. Riedl [this message]
2021-08-05 9:09 ` [PATCH v5 4/8] lkdtm/x86_64: Add test to hijack a patch mapping Christophe Leroy
2021-08-11 17:53 ` Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 5/8] powerpc/64s: Introduce temporary mm for Radix MMU Christopher M. Riedl
2021-08-05 9:27 ` Christophe Leroy
2021-08-11 18:02 ` Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 6/8] powerpc: Rework and improve STRICT_KERNEL_RWX patching Christopher M. Riedl
2021-08-05 9:34 ` Christophe Leroy
2021-08-11 18:10 ` Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 7/8] powerpc/64s: Initialize and use a temporary mm for patching on Radix Christopher M. Riedl
2021-08-05 9:48 ` Christophe Leroy
2021-08-11 18:28 ` Christopher M. Riedl
2021-07-13 5:31 ` [PATCH v5 8/8] lkdtm/powerpc: Fix code patching hijack test Christopher M. Riedl
2021-08-05 9:18 ` Christophe Leroy
2021-08-11 17:57 ` Christopher M. Riedl
2021-08-05 9:03 ` [PATCH v5 0/8] Use per-CPU temporary mappings for patching on Radix MMU Christophe Leroy
2021-08-11 17:49 ` Christopher M. Riedl
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