[Qemu-devel] [PATCH v2] elf-ops.h: fix int overflow in load_elf()

[Stefano Garzarella]

This patch fixes a possible integer overflow when we calculate
the total size of ELF segments loaded.

Reported-by: Coverity (CID 1405299)
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Stefano Garzarella <address@hidden>
---
v2:
 - not use error_report in load_elf() [Peter]
 - return ELF_LOAD_TOO_BIG
 - add Alex's R-b
---
 include/hw/elf_ops.h | 5 +++++
 include/hw/loader.h  | 1 +
 hw/core/loader.c     | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
index 1496d7e753..e07d276df7 100644
--- a/include/hw/elf_ops.h
+++ b/include/hw/elf_ops.h
@@ -485,6 +485,11 @@ static int glue(load_elf, SZ)(const char *name, int fd,
                 }
             }
 
+            if (mem_size > INT_MAX - total_size) {
+                ret = ELF_LOAD_TOO_BIG;
+                goto fail;
+            }
+
             /* address_offset is hack for kernel images that are
                linked at the wrong physical address.  */
             if (translate_fn) {
diff --git a/include/hw/loader.h b/include/hw/loader.h
index 07fd9286e7..48a96cd559 100644
--- a/include/hw/loader.h
+++ b/include/hw/loader.h
@@ -89,6 +89,7 @@ int load_image_gzipped(const char *filename, hwaddr addr, 
uint64_t max_sz);
 #define ELF_LOAD_NOT_ELF      -2
 #define ELF_LOAD_WRONG_ARCH   -3
 #define ELF_LOAD_WRONG_ENDIAN -4
+#define ELF_LOAD_TOO_BIG      -5
 const char *load_elf_strerror(int error);
 
 /** load_elf_ram_sym:
diff --git a/hw/core/loader.c b/hw/core/loader.c
index 32f7cc7c33..75eb56ddbb 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -338,6 +338,8 @@ const char *load_elf_strerror(int error)
         return "The image is from incompatible architecture";
     case ELF_LOAD_WRONG_ENDIAN:
         return "The image has incorrect endianness";
+    case ELF_LOAD_TOO_BIG:
+        return "The image segments are too big to load";
     default:
         return "Unknown error";
     }
-- 
2.21.0