From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:48290 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751071AbeAIGUc (ORCPT ); Tue, 9 Jan 2018 01:20:32 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 24976356D4 for ; Tue, 9 Jan 2018 06:20:32 +0000 (UTC) Received: from dhcp-13-208.nay.redhat.com (dhcp-13-208.nay.redhat.com [10.66.13.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6136E620A5 for ; Tue, 9 Jan 2018 06:20:31 +0000 (UTC) From: Zorro Lang Subject: [PATCH] db/print: bad character cause illegal memory access Date: Tue, 9 Jan 2018 14:20:27 +0800 Message-Id: <20180109062027.4570-1-zlang@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: linux-xfs@vger.kernel.org xfs_db can print specified field values, likes: # xfs_db -c "inode $inum" -c "print core.nblocks" $dev But when we give it some bad chararcters, the 'print' command will crash: # xfs_db -r -c "inode 67211167" -c "print core.*" /dev/mapper/rhel-root bad character in field * *** Error in `xfs_db': free(): invalid pointer: 0x00007fa116e937b8 *** ... (crash messages) ... # xfs_db -r -c "inode 67211167" -c "print core.\"" /dev/mapper/rhel-root missing closing quote *** Error in `xfs_db': free(): invalid pointer: 0x00007f6e8e3c37b8 *** ... (crash messages) ... The reason is xfs_db call ftok_free() to free ftok_t list, but flist_split() forgets to set the tail to NULL. That cause ftok_free() trys to free illegal memory address. Signed-off-by: Zorro Lang --- db/flist.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/db/flist.c b/db/flist.c index e11acbfc..1a875b95 100644 --- a/db/flist.c +++ b/db/flist.c @@ -371,11 +371,14 @@ flist_split( v = xmalloc(sizeof(*v)); v->tok = NULL; while (*s) { + v = xrealloc(v, (nv + 1) * sizeof(*v)); /* need to add string handling */ if (*s == '\"') { s++; /* skip first quote */ if ((a = strrchr(s, '\"')) == NULL) { dbprintf(_("missing closing quote %s\n"), s); + v[nv].tok = NULL; + v[nv].tokty = TT_END; ftok_free(v); return NULL; } @@ -393,19 +396,21 @@ flist_split( t = puncttypes[a - punctchars]; } else { dbprintf(_("bad character in field %s\n"), s); + v[nv].tok = NULL; + v[nv].tokty = TT_END; ftok_free(v); return NULL; } a = xmalloc(l + 1); strncpy(a, s, l); a[l] = '\0'; - v = xrealloc(v, (nv + 2) * sizeof(*v)); v[nv].tok = a; v[nv].tokty = t; nv++; s += l + tailskip; tailskip = 0; } + v = xrealloc(v, (nv + 1) * sizeof(*v)); v[nv].tok = NULL; v[nv].tokty = TT_END; return v; -- 2.13.6