[lvc-project] [PATCH] x86/kaslr: Fix potential dereference of NULL pointer.

[Daniil Dulov]

Pointer val can have NULL value. Then its value is assigned to the pointer p.
p is dereferenced by calling strcmp().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 4cdba14f84c9 ("x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' boot options")
Signed-off-by: Daniil Dulov <d.dulov at aladdin.ru>
---
 arch/x86/boot/compressed/kaslr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b92fffbe761f..51b3925d4d2d 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -291,7 +291,7 @@ static void handle_mem_options(void)
 		} else if (!strcmp(param, "mem")) {
 			char *p = val;
 
-			if (!strcmp(p, "nopentium"))
+			if (!p || !strcmp(p, "nopentium"))
 				continue;
 			mem_size = memparse(p, &p);
 			if (mem_size == 0)
-- 
2.25.1