Do not overflow the stackbased "nt" struct when reading non-conforming
PE files.
diff --git a/server/mapping.c b/server/mapping.c
index 984fa7c..92546c2 100644
--- a/server/mapping.c
+++ b/server/mapping.c
@@ -206,7 +206,7 @@
IMAGE_SECTION_HEADER *sec = NULL;
struct fd *fd;
off_t pos;
- int unix_fd, size;
+ int unix_fd, size, toread;
/* load the headers */
@@ -225,8 +225,8 @@
pos += sizeof(nt.FileHeader);
/* zero out Optional header in the case it's not present or partial */
memset(&nt.OptionalHeader, 0, sizeof(nt.OptionalHeader));
- if (pread( unix_fd, &nt.OptionalHeader, nt.FileHeader.SizeOfOptionalHeader,
- pos ) != nt.FileHeader.SizeOfOptionalHeader) goto error;
+ toread = min( sizeof(nt.OptionalHeader), nt.FileHeader.SizeOfOptionalHeader );
+ if (pread( unix_fd, &nt.OptionalHeader, toread, pos ) != toread) goto error;
pos += nt.FileHeader.SizeOfOptionalHeader;
/* load the section headers */