top: prevent buffer overflow potential in all routines

Whereas that original patch (since reversed) addressed
some symptoms related to manually edited config files,
this solution deals with root causes. And it goes much
beyond any single top field by protecting all of top's
fields. Henceforth, a duplicated field is not allowed.

Reference(s):
. original qualys patch
0114-top-Prevent-buffer-overflow-in-calibrate_fields.patch
commit c424a643318abfb534a692bd86c6a5e411ed2ebb

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.c b/top/top.c
index 80040f00c2cc0ff8ed1eb635d115511a9811ddf8..5088a8d6f98c840e6634648bc619cab69d936e57 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -3715,7 +3715,7 @@ static const char *config_file (FILE *fp, const char *name, float *delay) {
    *delay = (float)tmp_whole + (float)tmp_fract / 1000;
 
    for (i = 0 ; i < GROUPSMAX; i++) {
-      int x;
+      int n, x;
       WIN_t *w = &Winstk[i];
       p = fmtmk(N_fmt(RC_bad_entry_fmt), i+1, name);
 
@@ -3727,6 +3727,11 @@ static const char *config_file (FILE *fp, const char *name, float *delay) {
  too bad fscanf is not as flexible with his format string as snprintf
 error Hey, fix the above fscanf 'PFLAGSSIZ' dependency !
 #endif
+      // ensure there's been no manual alteration of fieldscur
+      for (n = 0 ; n < EU_MAXPFLGS; n++) {
+         if (strchr(w->rc.fieldscur, w->rc.fieldscur[n]) != strrchr(w->rc.fieldscur, w->rc.fieldscur[n]))
+            return p;
+      }
       // be tolerant of missing release 3.3.10 graph modes additions
       if (3 > fscanf(fp, "\twinflags=%d, sortindx=%d, maxtasks=%d, graph_cpus=%d, graph_mems=%d\n"
          , &w->rc.winflags, &w->rc.sortindx, &w->rc.maxtasks, &w->rc.graph_cpus, &w->rc.graph_mems))