lsmod path hardcoded in v4l/Makefile

lsmod path hardcoded in v4l/Makefile

[Matthias Schwarzott]

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Hi list!

It seems the path to lsmod tool is hardcoded in the Makefile for out-of-tree 
building of v4l-dvb.
Now at least gentoo has moved lsmod from /sbin to /bin.
Additionally it is bad style (or at least I am told so), to not rely on $PATH 
but hardcode pathes for tools that should be in $PATH.

So the attached patch removes the hardcoded /sbin from the lsmod call.

Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>

Regards
Matthias

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diff -r 65ec132f20df v4l/Makefile
--- a/v4l/Makefile	Wed May 27 15:53:00 2009 -0300
+++ b/v4l/Makefile	Thu May 28 10:05:04 2009 +0200
@@ -196,7 +196,7 @@
   inst-m	:= $(obj-m)
 endif
 
-v4l_modules := $(shell /sbin/lsmod|cut -d' ' -f1 ) $(patsubst %.ko,%,$(inst-m))
+v4l_modules := $(shell lsmod|cut -d' ' -f1 ) $(patsubst %.ko,%,$(inst-m))
 
 #################################################
 # locales seem to cause trouble sometimes.

Re: lsmod path hardcoded in v4l/Makefile

[Andy Walls]

On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> Hi list!
> 
> It seems the path to lsmod tool is hardcoded in the Makefile for out-of-tree 
> building of v4l-dvb.
> Now at least gentoo has moved lsmod from /sbin to /bin.
> Additionally it is bad style (or at least I am told so), to not rely on $PATH 
> but hardcode pathes for tools that should be in $PATH.

It's a potential security hole to rely on $PATH instead of absolute
paths when running a command as root.

Since many of the commnads in the Makefile rely on $PATH, including
executions of 'install' which usually would be run as root, I suppose
secuirty concerns don't matter.

-Andy

> So the attached patch removes the hardcoded /sbin from the lsmod call.
> 
> Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
> 
> Regards
> Matthias

Re: lsmod path hardcoded in v4l/Makefile

[Trent Piepho]

On Mon, 22 Jun 2009, Andy Walls wrote:
> On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> > Hi list!
> >
> > It seems the path to lsmod tool is hardcoded in the Makefile for out-of-tree
> > building of v4l-dvb.
> > Now at least gentoo has moved lsmod from /sbin to /bin.

Won't your patch cause breakage for everyone who hasn't moved lsmod from
/sbin and doesn't have sbin in the path?  Which was, and perhaps still is,
the most common situation?  It would be better to do something that does
not break things that used to work.

> > Additionally it is bad style (or at least I am told so), to not rely on $PATH
> > but hardcode pathes for tools that should be in $PATH.
>
> It's a potential security hole to rely on $PATH instead of absolute
> paths when running a command as root.
>
> Since many of the commnads in the Makefile rely on $PATH, including
> executions of 'install' which usually would be run as root, I suppose
> secuirty concerns don't matter.
>
> -Andy
>
> > So the attached patch removes the hardcoded /sbin from the lsmod call.
> >
> > Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
> >
> > Regards
> > Matthias
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
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>

Re: lsmod path hardcoded in v4l/Makefile

[Matthias Schwarzott]

On Dienstag, 23. Juni 2009, Trent Piepho wrote:
> On Mon, 22 Jun 2009, Andy Walls wrote:
> > On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> > > Hi list!
> > >
> > > It seems the path to lsmod tool is hardcoded in the Makefile for
> > > out-of-tree building of v4l-dvb.
> > > Now at least gentoo has moved lsmod from /sbin to /bin.
>
> Won't your patch cause breakage for everyone who hasn't moved lsmod from
> /sbin and doesn't have sbin in the path?  Which was, and perhaps still is,
> the most common situation?  It would be better to do something that does
> not break things that used to work.

root without sbin in path is bad and broken, isn't it?
If you really think this is too common, we could add
PATH=/sbin:/bin:$PATH
at the start of the Makefile.

Regards
Matthias

Re: lsmod path hardcoded in v4l/Makefile

[Theodore Kilgore]

On Mon, 22 Jun 2009, Andy Walls wrote:

> On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
>> Hi list!
>>
>> It seems the path to lsmod tool is hardcoded in the Makefile for out-of-tree
>> building of v4l-dvb.
>> Now at least gentoo has moved lsmod from /sbin to /bin.

Sorry, but is it considered impertinent to ask why that lsmod should be 
moved from /sbin (system binaries, and lsmod certainly is one of those) 
and stick it into /bin instead? Is there any cogent reason for doing a 
thing like that, which may have escaped my attention? Unless one is making 
some very small distro for some very small hardware and (say) one of /bin 
and /sbin is symlinked to the other, I find a change like that to be 
extremely puzzling. So, really. Why?

Theodore Kilgore

Re: lsmod path hardcoded in v4l/Makefile

[Matthias Schwarzott]

On Dienstag, 23. Juni 2009, Theodore Kilgore wrote:
> On Mon, 22 Jun 2009, Andy Walls wrote:
> > On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> >> Hi list!
> >>
> >> It seems the path to lsmod tool is hardcoded in the Makefile for
> >> out-of-tree building of v4l-dvb.
> >> Now at least gentoo has moved lsmod from /sbin to /bin.
>
> Sorry, but is it considered impertinent to ask why that lsmod should be
> moved from /sbin (system binaries, and lsmod certainly is one of those)
> and stick it into /bin instead? Is there any cogent reason for doing a

/sbin are binaries that only root should use. But lsmod can be used by users, 
too.
Suse also has only /bin/lsmod I think.
I don't know too much about the reason for the move, but it was long ago - 
version 0.9.11 contained that move and was released around year 2003.
Gentoo ebuild added /sbin/lsmod as compat symlink for things still hardcoding 
the path, but that was removed 2009 - 6 years should be enough.

> thing like that, which may have escaped my attention? Unless one is making
> some very small distro for some very small hardware and (say) one of /bin
> and /sbin is symlinked to the other, I find a change like that to be
> extremely puzzling. So, really. Why?
For a real answer to "why", do ask module-init-tools maintainer.

Regards
Matthias

Re: lsmod path hardcoded in v4l/Makefile

[Matthias Schwarzott]

On Dienstag, 23. Juni 2009, Andy Walls wrote:
> On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> > Hi list!
> >
> > It seems the path to lsmod tool is hardcoded in the Makefile for
> > out-of-tree building of v4l-dvb.
> > Now at least gentoo has moved lsmod from /sbin to /bin.
> > Additionally it is bad style (or at least I am told so), to not rely on
> > $PATH but hardcode pathes for tools that should be in $PATH.
>
> It's a potential security hole to rely on $PATH instead of absolute
> paths when running a command as root.

Shouldn't $PATH of root be considered safe? Else the distro or the system 
setup is doing something worse, and can't be improved by using fixed pathes 
in some scripts and Makefiles.

Regards
Matthias

Re: lsmod path hardcoded in v4l/Makefile

[Trent Piepho]

On Tue, 23 Jun 2009, Matthias Schwarzott wrote:
> > On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> > > It seems the path to lsmod tool is hardcoded in the Makefile for
> > > out-of-tree building of v4l-dvb.
> >
> Shouldn't $PATH of root be considered safe? Else the distro or the system

I believe make will set the variable whenever the makefile is used, even
when building as non-root.

It turns out that it was just lsmod with no path originally, but Michael
Krufky changed it back in 2005 (commit b0e7b40744ef) to have a hardcoded
path.  Then later in commit c91e7f84a1d6 the only use of 'v4l_modules' was
deleted, so we can just delete this line and not worry about sbin and
paths.

Mauro,

Please pull from http://linuxtv.org/hg/~tap/fix

for the following changeset:

build: Remove module list cruft
http://linuxtv.org/hg/~tap/fix?cmd=changeset;node=fb228bb1ad9f

Re: lsmod path hardcoded in v4l/Makefile

[Matthias Schwarzott]

On Dienstag, 23. Juni 2009, Trent Piepho wrote:
> On Tue, 23 Jun 2009, Matthias Schwarzott wrote:
> > > On Mon, 2009-06-22 at 16:36 +0200, Matthias Schwarzott wrote:
> > > > It seems the path to lsmod tool is hardcoded in the Makefile for
> > > > out-of-tree building of v4l-dvb.
> >
> > Shouldn't $PATH of root be considered safe? Else the distro or the system
>
> I believe make will set the variable whenever the makefile is used, even
> when building as non-root.
>
> It turns out that it was just lsmod with no path originally, but Michael
> Krufky changed it back in 2005 (commit b0e7b40744ef) to have a hardcoded
> path.  Then later in commit c91e7f84a1d6 the only use of 'v4l_modules' was
> deleted, so we can just delete this line and not worry about sbin and
> paths.
>
> Mauro,
>
> Please pull from http://linuxtv.org/hg/~tap/fix
>
> for the following changeset:
>
> build: Remove module list cruft
> http://linuxtv.org/hg/~tap/fix?cmd=changeset;node=fb228bb1ad9f

Hi Mauro!

is there any reason to not pull this besides time?

Regards
Matthias

Re: lsmod path hardcoded in v4l/Makefile

[Mauro Carvalho Chehab]

Em Tue, 21 Jul 2009 09:14:36 +0200
Matthias Schwarzott <zzam@gentoo.org> escreveu:

 
> Hi Mauro!
> 
> is there any reason to not pull this besides time?

Time is one reason, however, there's another:

It is not a good idea to run as root. Most people compile everything
with a normal user and then use "sudo" command to install/remove/insert
modules. Unfortunately, depending on the distribution, sudo inherits PATH from
the normal user, instead of root. Due to that, if you replace it for just
lsmod, it will fail for people that don't use gentoo.

Maybe good solution is to test if lsmod (and other similar tools) are at /sbin
or /usr/sbin. 

Alternatively, we can try to replace lsmod by something like (untested):

v4l_modules := $(shell PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin lsmod|cut -d' ' -f1 ) $(patsubst %.ko,%,$(inst-m))

> 
> Regards
> Matthias
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
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Cheers,
Mauro

Re: lsmod path hardcoded in v4l/Makefile

[Trent Piepho]

On Mon, 27 Jul 2009, Mauro Carvalho Chehab wrote:
> Em Tue, 21 Jul 2009 09:14:36 +0200
> Matthias Schwarzott <zzam@gentoo.org> escreveu:
> It is not a good idea to run as root. Most people compile everything
> with a normal user and then use "sudo" command to install/remove/insert
> modules. Unfortunately, depending on the distribution, sudo inherits PATH from
> the normal user, instead of root. Due to that, if you replace it for just
> lsmod, it will fail for people that don't use gentoo.
>
> Maybe good solution is to test if lsmod (and other similar tools) are at /sbin
> or /usr/sbin.
>
> Alternatively, we can try to replace lsmod by something like (untested):
>
> v4l_modules := $(shell PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin lsmod|cut -d' ' -f1 ) $(patsubst %.ko,%,$(inst-m))

Check my patch again, we can just delete the v4l_modules line as nothing
uses it.