From: "Christopher M. Riedl" <cmr@bluescreens.de>
To: linuxppc-dev@lists.ozlabs.org
Cc: tglx@linutronix.de, x86@kernel.org,
linux-hardening@vger.kernel.org, keescook@chromium.org
Subject: [PATCH v4 09/11] lkdtm/powerpc: Fix code patching hijack test
Date: Thu, 29 Apr 2021 02:20:55 -0500 [thread overview]
Message-ID: <20210429072057.8870-10-cmr@bluescreens.de> (raw)
In-Reply-To: <20210429072057.8870-1-cmr@bluescreens.de>
Code patching on powerpc with a STRICT_KERNEL_RWX uses a userspace
address in a temporary mm now. Use __put_user() to avoid write failures
due to KUAP when attempting a "hijack" on the patching address.
Signed-off-by: Christopher M. Riedl <cmr@bluescreens.de>
---
drivers/misc/lkdtm/perms.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 55c3bec6d3b72..af9bf285fe326 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -268,16 +268,7 @@ 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)
--
2.26.1
next prev parent reply other threads:[~2021-04-29 7:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-29 7:20 [PATCH v4 00/11] Use per-CPU temporary mappings for patching Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 01/11] powerpc: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 02/11] lkdtm/powerpc: Add test to hijack a patch mapping Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 03/11] x86_64: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 04/11] lkdtm/x86_64: Add test to hijack a patch mapping Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 05/11] powerpc/64s: Add ability to skip SLB preload Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 06/11] powerpc: Introduce temporary mm Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 07/11] powerpc/64s: Make slb_allocate_user() non-static Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 08/11] powerpc: Initialize and use a temporary mm for patching Christopher M. Riedl
2021-04-29 7:20 ` Christopher M. Riedl [this message]
2021-04-29 7:20 ` [PATCH v4 10/11] powerpc: Protect patching_mm with a lock Christopher M. Riedl
2021-04-29 7:20 ` [PATCH v4 11/11] powerpc: Use patch_instruction_unlocked() in loops Christopher M. Riedl
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