Date: Fri, 1 Apr 2011 15:37:31 +0400 From: Sergey Kandaurov <pluknet@freebsd.org> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-hackers@freebsd.org, FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: issue with devstat_buildmatch(3) and certain strings Message-ID: <AANLkTinK2u4G9m00RXUKK6C%2BBAtO7SdNNX8Er%2BY4YRNL@mail.gmail.com> In-Reply-To: <20110331210349.GA4112@freebsd.org> References: <20110331210349.GA4112@freebsd.org>
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On 1 April 2011 01:03, Alexander Best <arundel@freebsd.org> wrote:
> hi there,
>
> devstat_buildmatch(3) crashes with certain strings. you can test this by
> doing one of:
>
> iostat -t ","
> iostat -t ",,"
> iostat -t "da,"
> iostat -t ",da,"
> iostat -t ",da"
> iostat -t "da,scsi,"
> iostat -t ",da,scsi"
> iostat -t "da,,scsi"
[Someone told me, -hackers isn't appropriate for patches, Cc: -current.]
The problem is devstat(3) increments num_args regardless if strsep
returned NULL.
I think that should work (all your tests pass):
Index: lib/libdevstat/devstat.c
===================================================================
--- lib/libdevstat/devstat.c (revision 220102)
+++ lib/libdevstat/devstat.c (working copy)
@@ -1014,11 +1014,12 @@
* Break the (comma delimited) input string out into separate strings.
*/
for (tempstr = tstr, num_args = 0;
- (*tempstr = strsep(&match_str, ",")) != NULL && (num_args < 5);
- num_args++)
- if (**tempstr != '\0')
+ (*tempstr = strsep(&match_str, ",")) != NULL && (num_args < 5); )
+ if (**tempstr != '\0') {
+ num_args++;
if (++tempstr >= &tstr[5])
break;
+ }
/* The user gave us too many type arguments */
if (num_args > 3) {
Please review, and I will commit the patch.
--
wbr,
pluknet
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