[PATCH 3/5] efi_memory: avoid possible null pointer dereference

[Sughosh Ganu]

Populate the previous memory descriptor node pointer only after it's
parent struct has been initialised. The compiler fixes this logic to
do the right thing, but it is better to have correct code in place.

Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
---
 lib/efi_loader/efi_memory.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index bfadd6bd41..8d4f6e339d 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -138,7 +138,7 @@ static void efi_mem_sort(void)
 		merge_again = false;
 		list_for_each(lhandle, &efi_mem) {
 			struct efi_mem_list *lmem;
-			struct efi_mem_desc *prev = &prevmem->desc;
+			struct efi_mem_desc *prev;
 			struct efi_mem_desc *cur;
 			uint64_t pages;
 
@@ -149,6 +149,7 @@ static void efi_mem_sort(void)
 			}
 
 			cur = &lmem->desc;
+			prev = &prevmem->desc;
 
 			if ((desc_get_end(cur) == prev->physical_start) &&
 			    (prev->type == cur->type) &&
-- 
2.34.1