[PATCH] eif: cope with huge section offsets

[Paolo Bonzini <pbonzini@redhat.com>]

Check for overflow to avoid that fseek() receives a sign-extended value.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/qemu/osdep.h | 4 ++++
 hw/core/eif.c        | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index fe7c3c5f673..fdff07fd992 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -297,6 +297,10 @@ void QEMU_ERROR("code path is reachable")
 #error building with G_DISABLE_ASSERT is not supported
 #endif
 
+#ifndef OFF_MAX
+#define OFF_MAX (sizeof (off_t) == 8 ? INT64_MAX : INT32_MAX)
+#endif
+
 #ifndef O_LARGEFILE
 #define O_LARGEFILE 0
 #endif
diff --git a/hw/core/eif.c b/hw/core/eif.c
index 7f3b2edc9a7..cbcd80de58b 100644
--- a/hw/core/eif.c
+++ b/hw/core/eif.c
@@ -115,6 +115,10 @@ static bool read_eif_header(FILE *f, EifHeader *header, uint32_t *crc,
 
     for (int i = 0; i < MAX_SECTIONS; ++i) {
         header->section_offsets[i] = be64_to_cpu(header->section_offsets[i]);
+        if (header->section_offsets[i] > OFF_MAX) {
+            error_setg(errp, "Invalid EIF image. Section offset out of bounds");
+            return false;
+        }
     }
 
     for (int i = 0; i < MAX_SECTIONS; ++i) {
-- 
2.47.0