* Segmentation fault on some man pages
@ 2019-11-30 19:39 Milan P. Stanić
2019-12-02 21:05 ` Ingo Schwarze
0 siblings, 1 reply; 3+ messages in thread
From: Milan P. Stanić @ 2019-11-30 19:39 UTC (permalink / raw)
To: discuss
[-- Attachment #1: Type: text/plain, Size: 906 bytes --]
Hello,
Sorry if this is not right list to post bug report but I can't find
where to post it.
On Alpine linux (musl libc) we discovered 'Segmentation fault' when
running 'man nft' (nftables man page).
We have mandoc (named mdocml=1.14.5-r0 in our distribution) and it works
fine, except this for 'nft' man page.
This is excerpt from 'ltrace man nft':
putwchar(9472, 9472, 0x7fe813c0bbab, 0)
strcmp(nil, "\\^" <no return ...>
--- SIGSEGV (Segmentation fault) ---
+++ killed by SIGSEGV +++
I looked in source and found problem in tbl_term.c file.
I made crude hack by removing few lines in tbl_term.c and build mandoc
again and with these changes it works without (visible to me) problem
for man pages I tried and for nft man page.
I'm attaching patch I made, but I think it is not proper fix and hope
that some of you experienced in this will make proper fix.
File I'm attaching is just hint.
--
Tia
[-- Attachment #2: fix-tbl_term.patch --]
[-- Type: text/x-diff, Size: 757 bytes --]
--- a/tbl_term.c 2019-03-10 10:56:43.000000000 +0100
+++ b/tbl_term.c 2019-11-30 14:38:12.918969863 +0100
@@ -625,8 +626,7 @@
/* Print the horizontal line inside this column. */
lw = cpp == NULL || cpn == NULL ||
- (cpn->pos != TBL_CELL_DOWN &&
- (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
+ cpn->pos != TBL_CELL_DOWN
? hw : 0;
tbl_direct_border(tp, BHORIZ * lw,
col->width + col->spacing / 2);
@@ -669,8 +669,7 @@
/* The horizontal line inside the next column. */
rw = cpp == NULL || cpn == NULL ||
- (cpn->pos != TBL_CELL_DOWN &&
- (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
+ cpn->pos != TBL_CELL_DOWN
? hw : 0;
/* The line crossing at the end of this column. */
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Segmentation fault on some man pages
2019-11-30 19:39 Segmentation fault on some man pages Milan P. Stanić
@ 2019-12-02 21:05 ` Ingo Schwarze
2019-12-02 22:14 ` Milan P. Stanić
0 siblings, 1 reply; 3+ messages in thread
From: Ingo Schwarze @ 2019-12-02 21:05 UTC (permalink / raw)
To: Milan P. Stanić; +Cc: discuss
Hello Milan,
Milan P. Stanic wrote on Sat, Nov 30, 2019 at 08:39:26PM +0100:
> Sorry if this is not right list to post bug report
discuss@, tech@, or devel@ are all fine for bug reports.
- discuss@ is best when you think that many people may be affected
and/or if it feels important or serious
- tech@ is better for minor quirks that fewer people are likely
to be interested in
- devel@ provides as choice to report a bug privately if you
prefer that for whatever reason
> but I can't find where to post it.
https://mandoc.bsd.lv/contact.html
> On Alpine linux (musl libc) we discovered 'Segmentation fault' when
> running 'man nft' (nftables man page).
Thanks for reporting.
> We have mandoc (named mdocml=1.14.5-r0 in our distribution) and it works
> fine, except this for 'nft' man page.
>
> This is excerpt from 'ltrace man nft':
> putwchar(9472, 9472, 0x7fe813c0bbab, 0)
> strcmp(nil, "\\^" <no return ...>
> --- SIGSEGV (Segmentation fault) ---
> +++ killed by SIGSEGV +++
I tried to reporduce with the input file
https://manpages.debian.org/testing/nftables/nft.8.en.gz
but mandoc-current on OpenBSD-current does not crash.
Is that the exact version of the input file nft.8 that you are using?
If not, could you send a copy of the nft.8 that crashes for you
to me directly (not needed on the list)?
> I looked in source and found problem in tbl_term.c file.
> I made crude hack by removing few lines in tbl_term.c and build mandoc
> again and with these changes it works without (visible to me) problem
> for man pages I tried and for nft man page.
>
> I'm attaching patch I made, but I think it is not proper fix and hope
> that some of you experienced in this will make proper fix.
> File I'm attaching is just hint.
Hmmm... The code in mandoc-current does not match the code
on the "-"-lines of your patch below. Mandoc-current contains:
/* Print the horizontal line inside this column. */
lw = cpp == NULL || cpn == NULL ||
(cpn->pos != TBL_CELL_DOWN &&
(dpn == NULL || dpn->string == NULL ||
strcmp(dpn->string, "\\^") != 0))
? hw : 0;
[...]
/* The horizontal line inside the next column. */
rw = cpp == NULL || cpn == NULL ||
(cpn->pos != TBL_CELL_DOWN &&
(dpn == NULL || dpn->string == NULL ||
strcmp(dpn->string, "\\^") != 0))
? hw : 0;
I suspect the following commit might already have fixed your problem
about eight months ago:
https://cvsweb.bsd.lv/mandoc/tbl_term.c#rev1.70
https://cvsweb.bsd.lv/mandoc/tbl_term.c.diff?r1=1.69&r2=1.70
Does that fix the issue for you?
If so, consider adding a combined patch containing
rev.s 1.70 and 1.71 to your port until i roll a new release:
https://cvsweb.bsd.lv/mandoc/tbl_term.c.diff?r1=1.69&r2=1.71
Yours,
Ingo
> --- a/tbl_term.c 2019-03-10 10:56:43.000000000 +0100
> +++ b/tbl_term.c 2019-11-30 14:38:12.918969863 +0100
> @@ -625,8 +626,7 @@
> /* Print the horizontal line inside this column. */
>
> lw = cpp == NULL || cpn == NULL ||
> - (cpn->pos != TBL_CELL_DOWN &&
> - (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
> + cpn->pos != TBL_CELL_DOWN
> ? hw : 0;
> tbl_direct_border(tp, BHORIZ * lw,
> col->width + col->spacing / 2);
> @@ -669,8 +669,7 @@
> /* The horizontal line inside the next column. */
>
> rw = cpp == NULL || cpn == NULL ||
> - (cpn->pos != TBL_CELL_DOWN &&
> - (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
> + cpn->pos != TBL_CELL_DOWN
> ? hw : 0;
>
> /* The line crossing at the end of this column. */
--
To unsubscribe send an email to discuss+unsubscribe@mandoc.bsd.lv
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Segmentation fault on some man pages
2019-12-02 21:05 ` Ingo Schwarze
@ 2019-12-02 22:14 ` Milan P. Stanić
0 siblings, 0 replies; 3+ messages in thread
From: Milan P. Stanić @ 2019-12-02 22:14 UTC (permalink / raw)
To: discuss
Hello Ingo,
On Mon, 2019-12-02 at 22:05, Ingo Schwarze wrote:
> Hello Milan,
>
> Milan P. Stanic wrote on Sat, Nov 30, 2019 at 08:39:26PM +0100:
>
> > Sorry if this is not right list to post bug report
>
> discuss@, tech@, or devel@ are all fine for bug reports.
>
> - discuss@ is best when you think that many people may be affected
> and/or if it feels important or serious
> - tech@ is better for minor quirks that fewer people are likely
> to be interested in
> - devel@ provides as choice to report a bug privately if you
> prefer that for whatever reason
>
> > but I can't find where to post it.
>
> https://mandoc.bsd.lv/contact.html
Yes, I found this link and subscribed to discuss@
> > On Alpine linux (musl libc) we discovered 'Segmentation fault' when
> > running 'man nft' (nftables man page).
>
> Thanks for reporting.
>
> > We have mandoc (named mdocml=1.14.5-r0 in our distribution) and it works
^^^^^^
In Alpine linux we are using version 1.14.5 of mandoc/mdocml, which are
latest stable version, I think.
> > fine, except this for 'nft' man page.
> >
> > This is excerpt from 'ltrace man nft':
> > putwchar(9472, 9472, 0x7fe813c0bbab, 0)
> > strcmp(nil, "\\^" <no return ...>
> > --- SIGSEGV (Segmentation fault) ---
> > +++ killed by SIGSEGV +++
>
> I tried to reporduce with the input file
>
> https://manpages.debian.org/testing/nftables/nft.8.en.gz
>
> but mandoc-current on OpenBSD-current does not crash.
> Is that the exact version of the input file nft.8 that you are using?
> If not, could you send a copy of the nft.8 that crashes for you
> to me directly (not needed on the list)?
Of course, I will post it to your mail address to not fill mailing list
unnecessary.
> > I looked in source and found problem in tbl_term.c file.
> > I made crude hack by removing few lines in tbl_term.c and build mandoc
> > again and with these changes it works without (visible to me) problem
> > for man pages I tried and for nft man page.
> >
> > I'm attaching patch I made, but I think it is not proper fix and hope
> > that some of you experienced in this will make proper fix.
> > File I'm attaching is just hint.
>
> Hmmm... The code in mandoc-current does not match the code
> on the "-"-lines of your patch below. Mandoc-current contains:
>
> /* Print the horizontal line inside this column. */
>
> lw = cpp == NULL || cpn == NULL ||
> (cpn->pos != TBL_CELL_DOWN &&
> (dpn == NULL || dpn->string == NULL ||
> strcmp(dpn->string, "\\^") != 0))
> ? hw : 0;
> [...]
> /* The horizontal line inside the next column. */
>
> rw = cpp == NULL || cpn == NULL ||
> (cpn->pos != TBL_CELL_DOWN &&
> (dpn == NULL || dpn->string == NULL ||
> strcmp(dpn->string, "\\^") != 0))
> ? hw : 0;
>
> I suspect the following commit might already have fixed your problem
> about eight months ago:
>
> https://cvsweb.bsd.lv/mandoc/tbl_term.c#rev1.70
> https://cvsweb.bsd.lv/mandoc/tbl_term.c.diff?r1=1.69&r2=1.70
I found patch in Void linux source packages
https://github.com/void-linux/void-packages/blob/master/srcpkgs/mdocml/patches/fix-tbl-NULL-pointer-dereference.patch
which looks like it is taken from your link above
https://cvsweb.bsd.lv/mandoc/tbl_term.c.diff?r1=1.69&r2=1.70
> Does that fix the issue for you?
Yes, this patch fixes segmentation fault on Alpine.
> If so, consider adding a combined patch containing
> rev.s 1.70 and 1.71 to your port until i roll a new release:
>
> https://cvsweb.bsd.lv/mandoc/tbl_term.c.diff?r1=1.69&r2=1.71
Will try and see if it works.
Thank you for help
--
Best regards
> Yours,
> Ingo
>
>
> > --- a/tbl_term.c 2019-03-10 10:56:43.000000000 +0100
> > +++ b/tbl_term.c 2019-11-30 14:38:12.918969863 +0100
> > @@ -625,8 +626,7 @@
> > /* Print the horizontal line inside this column. */
> >
> > lw = cpp == NULL || cpn == NULL ||
> > - (cpn->pos != TBL_CELL_DOWN &&
> > - (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
> > + cpn->pos != TBL_CELL_DOWN
> > ? hw : 0;
> > tbl_direct_border(tp, BHORIZ * lw,
> > col->width + col->spacing / 2);
> > @@ -669,8 +669,7 @@
> > /* The horizontal line inside the next column. */
> >
> > rw = cpp == NULL || cpn == NULL ||
> > - (cpn->pos != TBL_CELL_DOWN &&
> > - (dpn == NULL || strcmp(dpn->string, "\\^") != 0))
> > + cpn->pos != TBL_CELL_DOWN
> > ? hw : 0;
> >
> > /* The line crossing at the end of this column. */
> --
> To unsubscribe send an email to discuss+unsubscribe@mandoc.bsd.lv
>
--
To unsubscribe send an email to discuss+unsubscribe@mandoc.bsd.lv
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-11-30 19:39 Segmentation fault on some man pages Milan P. Stanić
2019-12-02 21:05 ` Ingo Schwarze
2019-12-02 22:14 ` Milan P. Stanić
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