[PATCH] lkdtm: Add checks after calling kmalloc and vmalloc

[Jiasheng Jiang]

As the potential failure of the memory allocation,
it should be better to check the return value after
calling kmalloc and vmalloc and skip the execute_location
if fails.

Fixes: cc33c537c12f ("lkdtm: add "EXEC_*" triggers")
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
 drivers/misc/lkdtm/perms.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index b93404d65650..9ba927d74973 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -180,14 +180,16 @@ static void lkdtm_EXEC_STACK(void)
 static void lkdtm_EXEC_KMALLOC(void)
 {
 	u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
-	execute_location(kmalloc_area, CODE_WRITE);
+	if (kmalloc_area)
+		execute_location(kmalloc_area, CODE_WRITE);
 	kfree(kmalloc_area);
 }
 
 static void lkdtm_EXEC_VMALLOC(void)
 {
 	u32 *vmalloc_area = vmalloc(EXEC_SIZE);
-	execute_location(vmalloc_area, CODE_WRITE);
+	if (vmalloc_area)
+		execute_location(vmalloc_area, CODE_WRITE);
 	vfree(vmalloc_area);
 }
 
-- 
2.25.1