[RESEND PATCH v4 09/11] lkdtm/powerpc: Fix code patching hijack test
Christopher M. Riedl
cmr at linux.ibm.com
Thu May 6 14:34:50 AEST 2021
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 at linux.ibm.com>
---
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
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