fs: fix setserverprefs where long is larger than afs_int32

Make the fscanf and scanf format specifiers match the type of the
target variable.  This prevents trying to store a long int into an
afs_int32 variable which may be smaller, and overwriting neighbouring
data on the stack.

The effect on a 64-bit Linux system was that the high bits of "rank"
would overwrite the first 4 bytes of the scanned host name, causing
setserverprefs to fail with:
: couldn't resolve name.

Change-Id: I2100e7fe77a137257eb308ad127c151de84756bc
Reviewed-on: http://gerrit.openafs.org/5486
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: Derrick Brashear <shadow@dementix.org>

diff --git a/src/venus/fs.c b/src/venus/fs.c
index 8cc842f..31d20d4 100644 (file)
--- a/src/venus/fs.c
+++ b/src/venus/fs.c
@@ -3150,7 +3150,7 @@ SetPrefCmd(struct cmd_syndesc *as, void *arock)
     afs_int32 code;
     struct cmd_item *ti;
     char name[80];
-    afs_int32 rank;
+    int rank;
     struct setspref *ssp;
     int error = 0;             /* -1 means error message printed,
                                 * >0 means errno value for unprinted message */
@@ -3177,7 +3177,7 @@ SetPrefCmd(struct cmd_syndesc *as, void *arock)
            perror(ti->data);
            error = -1;
        } else {
-           while (fscanf(infd, "%79s%ld", name, (long int *)&rank) != EOF) {
+           while (fscanf(infd, "%79s%d", name, &rank) != EOF) {
                code = addServer(name, (unsigned short)rank);
                if (code)
                    error = code;
@@ -3187,7 +3187,7 @@ SetPrefCmd(struct cmd_syndesc *as, void *arock)
 
     ti = as->parms[3].items;   /* -stdin */
     if (ti) {
-       while (scanf("%79s%ld", name, (long int *)&rank) != EOF) {
+       while (scanf("%79s%d", name, &rank) != EOF) {
            code = addServer(name, (unsigned short)rank);
            if (code)
                error = code;