s3:printing: Fix size check in get_file_version()

This fixes compilation with -Wstrict-overflow=2

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/source3/printing/nt_printing.c b/source3/printing/nt_printing.c
index 2e500f18c7d249fce970ab1fa3c1ade549e9974f..241af37743ef9b1f0ecb59239743938bbf11f982 100644 (file)
--- a/source3/printing/nt_printing.c
+++ b/source3/printing/nt_printing.c
@@ -485,19 +485,31 @@ static int get_file_version(files_struct *fsp, char *fname,uint32_t *major, uint
                                /* Potential match data crosses buf boundry, move it to beginning
                                 * of buf, and fill the buf with as much as it will hold. */
                                if (i>byte_count-VS_VERSION_INFO_SIZE) {
-                                       int bc;
+                                       ssize_t amount_read;
+                                       ssize_t amount_unused = byte_count-i;
 
-                                       memcpy(buf, &buf[i], byte_count-i);
-                                       if ((bc = vfs_read_data(fsp, &buf[byte_count-i], VS_NE_BUF_SIZE-
-                                                                  (byte_count-i))) < 0) {
+                                       memmove(buf, &buf[i], amount_unused);
+                                       amount_read = vfs_read_data(fsp,
+                                               &buf[amount_unused],
+                                               VS_NE_BUF_SIZE- amount_unused);
+                                       if (amount_read < 0) {
 
                                                DEBUG(0,("get_file_version: NE file [%s] Read error, errno=%d\n",
                                                                 fname, errno));
                                                goto error_exit;
                                        }
 
-                                       byte_count = bc + (byte_count - i);
-                                       if (byte_count<VS_VERSION_INFO_SIZE) break;
+                                       if (amount_read + amount_unused <
+                                                       amount_read) {
+                                               /* Check for integer wrap. */
+                                               break;
+                                       }
+
+                                       byte_count = amount_read +
+                                                    amount_unused;
+                                       if (byte_count < VS_VERSION_INFO_SIZE) {
+                                               break;
+                                       }
 
                                        i = 0;
                                }