s3:utils: Fix stack smashing in net offlinejoin

Cast from 'uint32_t *' (aka 'unsigned int *') to 'size_t *' (aka
'unsigned long *') increases required alignment from 4 to 8

==10343==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffdc6784fc0 at pc 0x7f339f1ea500 bp 0x7ffdc6784ed0 sp 0x7ffdc6784ec8
WRITE of size 8 at 0x7ffdc6784fc0 thread T0
    #0 0x7f339f1ea4ff in fd_load ../../lib/util/util_file.c:220
    #1 0x7f339f1ea5a4 in file_load ../../lib/util/util_file.c:245
    #2 0x56363209a596 in net_offlinejoin_requestodj ../../source3/utils/net_offlinejoin.c:267
    #3 0x56363209a9d0 in net_offlinejoin ../../source3/utils/net_offlinejoin.c:74
    #4 0x56363208f61c in net_run_function ../../source3/utils/net_util.c:453
    #5 0x563631fe8a9f in main ../../source3/utils/net.c:1358
    #6 0x7f339b22c5af in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #7 0x7f339b22c678 in __libc_start_main_impl ../csu/libc-start.c:381
    #8 0x563631faf374 in _start ../sysdeps/x86_64/start.S:115

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15257

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Mon Dec  5 12:05:24 UTC 2022 on sn-devel-184

diff --git a/source3/utils/net_offlinejoin.c b/source3/utils/net_offlinejoin.c
index ef56ba9fce80df4224e0a1bdbbc8b75cbfff1b23..03e5df0eace97e4291a0c6ae62e7fe49d29b42c3 100644 (file)
--- a/source3/utils/net_offlinejoin.c
+++ b/source3/utils/net_offlinejoin.c
@@ -237,7 +237,7 @@ int net_offlinejoin_requestodj(struct net_context *c,
 {
        NET_API_STATUS status;
        uint8_t *provision_bin_data = NULL;
-       uint32_t provision_bin_data_size = 0;
+       size_t provision_bin_data_size = 0;
        uint32_t options = NETSETUP_PROVISION_ONLINE_CALLER;
        const char *loadfile = NULL;
        const char *windows_path = NULL;
@@ -264,12 +264,17 @@ int net_offlinejoin_requestodj(struct net_context *c,
 #endif
        }
 
-       provision_bin_data = (uint8_t *)file_load(loadfile,
-                       (size_t *)&provision_bin_data_size, 0, c);
+       provision_bin_data =
+               (uint8_t *)file_load(loadfile, &provision_bin_data_size, 0, c);
        if (provision_bin_data == NULL) {
                d_printf("Failed to read loadfile: %s\n", loadfile);
                return -1;
        }
+       if (provision_bin_data_size > UINT32_MAX) {
+               d_printf("provision binary data size too big: %zu\n",
+                        provision_bin_data_size);
+               return -1;
+       }
 
        status = NetRequestOfflineDomainJoin(provision_bin_data,
                                             provision_bin_data_size,