hexdump: do not segfault when iterating over an empty format string

Signed-off-by: Ondrej Oprala <ooprala@redhat.com>

diff --git a/tests/commands.sh b/tests/commands.sh
index db1d4ac6b5638a03d4b6644d1eda9d83f8941453..3672095480f6214c0d0c4df508da7d173d61977e 100644 (file)
--- a/tests/commands.sh
+++ b/tests/commands.sh
@@ -62,3 +62,4 @@ TS_CMD_FINDMNT=${TS_CMD_FINDMNT-"$top_builddir/findmnt"}
 
 TS_CMD_FDISK=${TS_CMD_FDISK-"$top_builddir/fdisk"}
 
+TS_CMD_HEXDUMP=${TS_CMD_HEXDUMP-"$top_builddir/hexdump"}

diff --git a/tests/expected/hexdump/empty-format b/tests/expected/hexdump/empty-format
new file mode 100644 (file)
index 0000000..9d60796
--- /dev/null
+++ b/tests/expected/hexdump/empty-format
@@ -0,0 +1 @@
+11
\ No newline at end of file

diff --git a/tests/ts/hexdump/empty-format b/tests/ts/hexdump/empty-format
new file mode 100755 (executable)
index 0000000..4a3e528
--- /dev/null
+++ b/tests/ts/hexdump/empty-format
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# This file is part of util-linux.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This file is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+TS_TOPDIR="$(dirname $0)/../.."
+TS_DESC="format-strings"
+
+. $TS_TOPDIR/functions.sh
+ts_init "$*"
+
+INPUT=$(printf \\1)
+$TS_CMD_HEXDUMP -n1 -ve '2 "" "%x"' <<< $INPUT 2>&1 >> $TS_OUTPUT
+
+$TS_CMD_HEXDUMP -n1 -ve '4 "%x"' -e '2 ""' <<< $INPUT 2>&1 >> $TS_OUTPUT
+
+ts_finalize

diff --git a/text-utils/parse.c b/text-utils/parse.c
index 5f1e2bda7767a07cba649c3e11f5a1e160eab164..bd9696108647dd2aef5a935af81e977f232c3c72 100644 (file)
--- a/text-utils/parse.c
+++ b/text-utils/parse.c
@@ -421,13 +421,15 @@ isint2:                                   switch(fu->bcnt) {
                    !(fu->flags&F_SETREP) && fu->bcnt)
                        fu->reps += (blocksize - fs->bcnt) / fu->bcnt;
                if (fu->reps > 1) {
-                       for (pr = fu->nextpr;; pr = pr->nextpr)
-                               if (!pr->nextpr)
-                                       break;
-                       for (p1 = pr->fmt, p2 = NULL; *p1; ++p1)
-                               p2 = isspace((unsigned char)*p1) ? p1 : NULL;
-                       if (p2)
-                               pr->nospace = p2;
+                       if (fu->nextpr) {
+                               for (pr = fu->nextpr; ; pr = pr->nextpr)
+                                       if (!pr->nextpr)
+                                               break;
+                               for (p1 = pr->fmt, p2 = NULL; *p1; ++p1)
+                                       p2 = isspace((unsigned char)*p1) ? p1 : NULL;
+                               if (p2)
+                                       pr->nospace = p2;
+                       }
                }
        }
 }