* [PATCH] srp_daemon: Avoid extra permissions for the lock file
@ 2020-08-19 14:17 Sergey Gorenko
2020-09-14 9:24 ` Sergey Gorenko
2020-09-14 16:56 ` Bart Van Assche
0 siblings, 2 replies; 6+ messages in thread
From: Sergey Gorenko @ 2020-08-19 14:17 UTC (permalink / raw)
To: bvanassche; +Cc: linux-rdma, Sergey Gorenko, Max Gurtovoy
There is no need to create a world-writable lock file.
It's enough to have an RW permission for the file owner only.
Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
---
srp_daemon/srp_daemon.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/srp_daemon/srp_daemon.c b/srp_daemon/srp_daemon.c
index f14d9f56c9f2..fcf94537cebb 100644
--- a/srp_daemon/srp_daemon.c
+++ b/srp_daemon/srp_daemon.c
@@ -142,7 +142,6 @@ static int check_process_uniqueness(struct config_t *conf)
return -1;
}
- fchmod(fd, S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH);
if (0 != lockf(fd, F_TLOCK, 0)) {
pr_err("failed to lock %s (errno: %d). possibly another "
"srp_daemon is locking it\n", path, errno);
--
2.21.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH] srp_daemon: Avoid extra permissions for the lock file
2020-08-19 14:17 [PATCH] srp_daemon: Avoid extra permissions for the lock file Sergey Gorenko
@ 2020-09-14 9:24 ` Sergey Gorenko
2020-09-14 16:50 ` Bart Van Assche
2020-09-14 16:56 ` Bart Van Assche
1 sibling, 1 reply; 6+ messages in thread
From: Sergey Gorenko @ 2020-09-14 9:24 UTC (permalink / raw)
To: bvanassche; +Cc: linux-rdma, Max Gurtovoy
> From: Sergey Gorenko <sergeygo@nvidia.com>
> Sent: Wednesday, August 19, 2020 5:18 PM
> To: bvanassche@acm.org
> Cc: linux-rdma@vger.kernel.org; Sergey Gorenko <sergeygo@nvidia.com>;
> Max Gurtovoy <mgurtovoy@nvidia.com>
> Subject: [PATCH] srp_daemon: Avoid extra permissions for the lock file
>
> There is no need to create a world-writable lock file.
> It's enough to have an RW permission for the file owner only.
>
> Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> ---
> srp_daemon/srp_daemon.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/srp_daemon/srp_daemon.c b/srp_daemon/srp_daemon.c index
> f14d9f56c9f2..fcf94537cebb 100644
> --- a/srp_daemon/srp_daemon.c
> +++ b/srp_daemon/srp_daemon.c
> @@ -142,7 +142,6 @@ static int check_process_uniqueness(struct config_t
> *conf)
> return -1;
> }
>
> - fchmod(fd,
> S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH);
> if (0 != lockf(fd, F_TLOCK, 0)) {
> pr_err("failed to lock %s (errno: %d). possibly another "
> "srp_daemon is locking it\n", path, errno);
> --
> 2.21.1
Hi Bart,
Could you review the patch? I'm asking for you because you are specified as a maintainer for srp_daemon in rdma-core.
Regards,
Sergey
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] srp_daemon: Avoid extra permissions for the lock file
2020-08-19 14:17 [PATCH] srp_daemon: Avoid extra permissions for the lock file Sergey Gorenko
2020-09-14 9:24 ` Sergey Gorenko
@ 2020-09-14 16:56 ` Bart Van Assche
2020-09-15 8:10 ` Sergey Gorenko
1 sibling, 1 reply; 6+ messages in thread
From: Bart Van Assche @ 2020-09-14 16:56 UTC (permalink / raw)
To: Sergey Gorenko; +Cc: linux-rdma, Max Gurtovoy
On 2020-08-19 07:17, Sergey Gorenko wrote:
> There is no need to create a world-writable lock file.
> It's enough to have an RW permission for the file owner only.
>
> Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> ---
> srp_daemon/srp_daemon.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/srp_daemon/srp_daemon.c b/srp_daemon/srp_daemon.c
> index f14d9f56c9f2..fcf94537cebb 100644
> --- a/srp_daemon/srp_daemon.c
> +++ b/srp_daemon/srp_daemon.c
> @@ -142,7 +142,6 @@ static int check_process_uniqueness(struct config_t *conf)
> return -1;
> }
>
> - fchmod(fd, S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH);
> if (0 != lockf(fd, F_TLOCK, 0)) {
> pr_err("failed to lock %s (errno: %d). possibly another "
> "srp_daemon is locking it\n", path, errno);
I think the fchmod() call was introduced by commit ee138ce1e40d ("Cause
srp_daemon launch to fail if another srp_daemon is already working on the
same HCA port."). Has it been verified that with this change applied that
mechanism still works?
Anyway, please add a reference to that commit in the patch description.
Thanks,
Bart.
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] srp_daemon: Avoid extra permissions for the lock file
2020-09-14 16:56 ` Bart Van Assche
@ 2020-09-15 8:10 ` Sergey Gorenko
2020-09-15 20:32 ` Bart Van Assche
0 siblings, 1 reply; 6+ messages in thread
From: Sergey Gorenko @ 2020-09-15 8:10 UTC (permalink / raw)
To: Bart Van Assche; +Cc: linux-rdma, Max Gurtovoy
> -----Original Message-----
> From: Bart Van Assche <bvanassche@acm.org>
> Sent: Monday, September 14, 2020 7:56 PM
> To: Sergey Gorenko <sergeygo@nvidia.com>
> Cc: linux-rdma@vger.kernel.org; Max Gurtovoy <mgurtovoy@nvidia.com>
> Subject: Re: [PATCH] srp_daemon: Avoid extra permissions for the lock file
>
> On 2020-08-19 07:17, Sergey Gorenko wrote:
> > There is no need to create a world-writable lock file.
> > It's enough to have an RW permission for the file owner only.
> >
> > Signed-off-by: Sergey Gorenko <sergeygo@nvidia.com>
> > Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> > ---
> > srp_daemon/srp_daemon.c | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/srp_daemon/srp_daemon.c b/srp_daemon/srp_daemon.c index
> > f14d9f56c9f2..fcf94537cebb 100644
> > --- a/srp_daemon/srp_daemon.c
> > +++ b/srp_daemon/srp_daemon.c
> > @@ -142,7 +142,6 @@ static int check_process_uniqueness(struct
> config_t *conf)
> > return -1;
> > }
> >
> > - fchmod(fd,
> S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH);
> > if (0 != lockf(fd, F_TLOCK, 0)) {
> > pr_err("failed to lock %s (errno: %d). possibly another "
> > "srp_daemon is locking it\n", path, errno);
>
> I think the fchmod() call was introduced by commit ee138ce1e40d ("Cause
> srp_daemon launch to fail if another srp_daemon is already working on the
> same HCA port."). Has it been verified that with this change applied that
> mechanism still works?
>
> Anyway, please add a reference to that commit in the patch description.
>
> Thanks,
>
> Bart.
>
Bart,
I tested the patch for the following scenarios:
* Start the srp_daemon service when srp_daemon is not running and the lock file does not exist.
* Start the srp_daemon service when srp_daemon is not running and the lock file exists.
* Start the srp_daemon service when srp_daemon is running and the lock file exists.
* Start the srp_daemon service when srp_daemon is running and the lock file exists and the file owner is not root. (Such scenario can happen if someone tries to run srp_daemon manually as not root. The srp_daemon fails in this case, but the lock file is created). This case is handled successfully even without the fchmod() call because the srp_daemon service starts srp_daemon as root.
I do not know any case when fchmod() is needed. And it does not look like a good idea to create a word-writable file owned by root. That's why I want to remove the fchmod() call.
Do you have an idea when the fchmod() call can be needed?
If you have no other objections, I will add the fixes line and send V1.
Thanks,
Sergey
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] srp_daemon: Avoid extra permissions for the lock file
2020-09-15 8:10 ` Sergey Gorenko
@ 2020-09-15 20:32 ` Bart Van Assche
0 siblings, 0 replies; 6+ messages in thread
From: Bart Van Assche @ 2020-09-15 20:32 UTC (permalink / raw)
To: Sergey Gorenko; +Cc: linux-rdma, Max Gurtovoy
On 2020-09-15 01:10, Sergey Gorenko wrote:
> I tested the patch for the following scenarios:
> * Start the srp_daemon service when srp_daemon is not running and the lock file does not exist.
> * Start the srp_daemon service when srp_daemon is not running and the lock file exists.
> * Start the srp_daemon service when srp_daemon is running and the lock file exists.
> * Start the srp_daemon service when srp_daemon is running and the lock file exists and the file owner is not root. (Such scenario can happen if someone tries to run srp_daemon manually as not root. The srp_daemon fails in this case, but the lock file is created). This case is handled successfully even without the fchmod() call because the srp_daemon service starts srp_daemon as root.
>
> I do not know any case when fchmod() is needed. And it does not look like a good idea to create a word-writable file owned by root. That's why I want to remove the fchmod() call.
>
> Do you have an idea when the fchmod() call can be needed?
>
> If you have no other objections, I will add the fixes line and send V1.
Thanks Sergey for having shared all this information. I think this testing
is sufficient. Hence:
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-09-15 20:34 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-08-19 14:17 [PATCH] srp_daemon: Avoid extra permissions for the lock file Sergey Gorenko
2020-09-14 9:24 ` Sergey Gorenko
2020-09-14 16:50 ` Bart Van Assche
2020-09-14 16:56 ` Bart Van Assche
2020-09-15 8:10 ` Sergey Gorenko
2020-09-15 20:32 ` Bart Van Assche
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