Hi,
On Thu, Dec 11, 2014 at 05:22:28PM +0100, Marcel Mol wrote:
> /proc/<pid>/io is only readable by the pid owner, while files
> like stat, statm and status are world readable.
> I see no reason why io statistics should be hidden.
> This patch makes io also world readable so process io counts
> can be analysed without root permissions.
As Andy noted this should be the other way around! so unless you have
a real usecase, this will revert previous patch by Vasiliy that closed
some info leaks...
https://lkml.org/lkml/2011/7/27/459
Thanks!
> Signed-off-by: Marcel Mol <[email protected]>
> ---
> fs/proc/base.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 772efa4..7bd8dbe 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2563,7 +2563,7 @@ static const struct pid_entry tgid_base_stuff[] = {
> REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
> #endif
> #ifdef CONFIG_TASK_IO_ACCOUNTING
> - ONE("io", S_IRUSR, proc_tgid_io_accounting),
> + ONE("io", S_IRUGO, proc_tgid_io_accounting),
> #endif
> #ifdef CONFIG_HARDWALL
> ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> @@ -2904,7 +2904,7 @@ static const struct pid_entry tid_base_stuff[] = {
> REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
> #endif
> #ifdef CONFIG_TASK_IO_ACCOUNTING
> - ONE("io", S_IRUSR, proc_tid_io_accounting),
> + ONE("io", S_IRUGO, proc_tid_io_accounting),
> #endif
> #ifdef CONFIG_HARDWALL
> ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> --
> 1.9.3
>
>
--
Djalal Harouni
http://opendz.org
On Thu, Dec 11, 2014 at 08:29:11PM +0100, Djalal Harouni wrote:
> Hi,
>
> On Thu, Dec 11, 2014 at 05:22:28PM +0100, Marcel Mol wrote:
> > /proc/<pid>/io is only readable by the pid owner, while files
> > like stat, statm and status are world readable.
> > I see no reason why io statistics should be hidden.
> > This patch makes io also world readable so process io counts
> > can be analysed without root permissions.
> As Andy noted this should be the other way around! so unless you have
> a real usecase, this will revert previous patch by Vasiliy that closed
> some info leaks...
> https://lkml.org/lkml/2011/7/27/459
>
> Thanks!
Hi Djalal, thanks for pointing this out. I did look for info like this,
but did not look that far back. I can see the issues Vasiliy points out.
I do not have a real important usecase, but it is just convenience.
On my home (personal) workstation I trust noone is looking for my
password length in ssh or ftp, but I sometimes do like to see what
process is keeping my disk busy. And I want to limit switching to
root...
So I guess I'm more interested in the read_byte, write_bytes and
cancelled_write_bytes fields (Per physical disk or filesystem
preferably.)
Would that give away any sensitive information?
If not maybe a separate /proc/PID/dio can be created to show only
these fields.
Thanks.
-Marcel
>
> > Signed-off-by: Marcel Mol <[email protected]>
> > ---
> > fs/proc/base.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/proc/base.c b/fs/proc/base.c
> > index 772efa4..7bd8dbe 100644
> > --- a/fs/proc/base.c
> > +++ b/fs/proc/base.c
> > @@ -2563,7 +2563,7 @@ static const struct pid_entry tgid_base_stuff[] = {
> > REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
> > #endif
> > #ifdef CONFIG_TASK_IO_ACCOUNTING
> > - ONE("io", S_IRUSR, proc_tgid_io_accounting),
> > + ONE("io", S_IRUGO, proc_tgid_io_accounting),
> > #endif
> > #ifdef CONFIG_HARDWALL
> > ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> > @@ -2904,7 +2904,7 @@ static const struct pid_entry tid_base_stuff[] = {
> > REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
> > #endif
> > #ifdef CONFIG_TASK_IO_ACCOUNTING
> > - ONE("io", S_IRUSR, proc_tid_io_accounting),
> > + ONE("io", S_IRUGO, proc_tid_io_accounting),
> > #endif
> > #ifdef CONFIG_HARDWALL
> > ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> > --
> > 1.9.3
> >
> >
>
> --
> Djalal Harouni
> http://opendz.org
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
======-------- Marcel J.E. Mol MESA Consulting B.V.
=======--------- ph. +31-(0)6-54724868 P.O. Box 112
=======--------- [email protected] 2630 AC Nootdorp
__==== http://www.mesa.nl ---____U_n_i_x______I_n_t_e_r_n_e_t____ The Netherlands ____
They couldn't think of a number, Linux user 1148 -- counter.li.org
so they gave me a name! -- Rupert Hine -- http://www.ruperthine.com
Hi Marcel (sorry for my late response),
On Fri, Dec 12, 2014 at 12:04:53AM +0100, Marcel J.E. Mol wrote:
> On Thu, Dec 11, 2014 at 08:29:11PM +0100, Djalal Harouni wrote:
> > Hi,
> >
> > On Thu, Dec 11, 2014 at 05:22:28PM +0100, Marcel Mol wrote:
> > > /proc/<pid>/io is only readable by the pid owner, while files
> > > like stat, statm and status are world readable.
> > > I see no reason why io statistics should be hidden.
> > > This patch makes io also world readable so process io counts
> > > can be analysed without root permissions.
> > As Andy noted this should be the other way around! so unless you have
> > a real usecase, this will revert previous patch by Vasiliy that closed
> > some info leaks...
> > https://lkml.org/lkml/2011/7/27/459
> >
> > Thanks!
>
> Hi Djalal, thanks for pointing this out. I did look for info like this,
> but did not look that far back. I can see the issues Vasiliy points out.
>
> I do not have a real important usecase, but it is just convenience.
> On my home (personal) workstation I trust noone is looking for my
> password length in ssh or ftp, but I sometimes do like to see what
> process is keeping my disk busy. And I want to limit switching to
> root...
Even if capabilities are not the best model, but they are useful here,
just use a small helper (aliased to whatever you want) that have a
hardcoded path to /proc/%u/io ,later give it CAP_DAC_OVERRIDE and
CAP_SYS_PTRACE
> So I guess I'm more interested in the read_byte, write_bytes and
> cancelled_write_bytes fields (Per physical disk or filesystem
> preferably.)
> Would that give away any sensitive information?
I'm not sure here, perhaps a matter of time before someone else
interested pops up with a reaserch on this?!
> If not maybe a separate /proc/PID/dio can be created to show only
> these fields.
Hmm, you could try if you think that it can be accepted! but do know
that these days new procfs features are rare unless they are justified
I don't know what others think about this.
> Thanks.
> -Marcel
>
> >
> > > Signed-off-by: Marcel Mol <[email protected]>
> > > ---
> > > fs/proc/base.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/fs/proc/base.c b/fs/proc/base.c
> > > index 772efa4..7bd8dbe 100644
> > > --- a/fs/proc/base.c
> > > +++ b/fs/proc/base.c
> > > @@ -2563,7 +2563,7 @@ static const struct pid_entry tgid_base_stuff[] = {
> > > REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
> > > #endif
> > > #ifdef CONFIG_TASK_IO_ACCOUNTING
> > > - ONE("io", S_IRUSR, proc_tgid_io_accounting),
> > > + ONE("io", S_IRUGO, proc_tgid_io_accounting),
> > > #endif
> > > #ifdef CONFIG_HARDWALL
> > > ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> > > @@ -2904,7 +2904,7 @@ static const struct pid_entry tid_base_stuff[] = {
> > > REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
> > > #endif
> > > #ifdef CONFIG_TASK_IO_ACCOUNTING
> > > - ONE("io", S_IRUSR, proc_tid_io_accounting),
> > > + ONE("io", S_IRUGO, proc_tid_io_accounting),
> > > #endif
> > > #ifdef CONFIG_HARDWALL
> > > ONE("hardwall", S_IRUGO, proc_pid_hardwall),
> > > --
> > > 1.9.3
> > >
> > >
> >
> > --
> > Djalal Harouni
> > http://opendz.org
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
>
> --
> ======-------- Marcel J.E. Mol MESA Consulting B.V.
> =======--------- ph. +31-(0)6-54724868 P.O. Box 112
> =======--------- [email protected] 2630 AC Nootdorp
> __==== http://www.mesa.nl ---____U_n_i_x______I_n_t_e_r_n_e_t____ The Netherlands ____
> They couldn't think of a number, Linux user 1148 -- counter.li.org
> so they gave me a name! -- Rupert Hine -- http://www.ruperthine.com
--
Djalal Harouni
http://opendz.org