The patch titled
Subject: pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
has been added to the -mm tree. Its filename is
pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Ben Segall <bsegall@xxxxxxxxxx>
Subject: pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
setpriority(PRIO_USER, 0, x) will change the priority of tasks outside of
the current pid namespace. This is in contrast to both the other modes of
setpriority and the example of kill(-1). Fix this. getpriority and
ioprio have the same failure mode, fix them too.
Eric said:
: After some more thinking about it this patch sounds justifiable.
:
: My goal with namespaces is not to build perfect isolation mechanisms
: as that can get into ill defined territory, but to build well defined
: mechanisms. And to handle the corner cases so you can use only
: a single namespace with well defined results.
:
: In this case you have found the two interfaces I am aware of that
: identify processes by uid instead of by pid. Which quite frankly is
: weird. Unfortunately the weird unexpected cases are hard to handle
: in the usual way.
:
: I was hoping for a little more information. Changes like this one we
: have to be careful of because someone might be depending on the current
: behavior. I don't think they are and I do think this make sense as part
: of the pid namespace.
Signed-off-by: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Ambrose Feinstein <ambrose@xxxxxxxxxx>
Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
block/ioprio.c | 6 ++++--
kernel/sys.c | 4 ++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff -puN block/ioprio.c~pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode block/ioprio.c
--- a/block/ioprio.c~pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode
+++ a/block/ioprio.c
@@ -123,7 +123,8 @@ SYSCALL_DEFINE3(ioprio_set, int, which,
break;
do_each_thread(g, p) {
- if (!uid_eq(task_uid(p), uid))
+ if (!uid_eq(task_uid(p), uid) ||
+ !task_pid_vnr(p))
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
@@ -220,7 +221,8 @@ SYSCALL_DEFINE2(ioprio_get, int, which,
break;
do_each_thread(g, p) {
- if (!uid_eq(task_uid(p), user->uid))
+ if (!uid_eq(task_uid(p), user->uid) ||
+ !task_pid_vnr(p))
continue;
tmpio = get_task_ioprio(p);
if (tmpio < 0)
diff -puN kernel/sys.c~pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode kernel/sys.c
--- a/kernel/sys.c~pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode
+++ a/kernel/sys.c
@@ -222,7 +222,7 @@ SYSCALL_DEFINE3(setpriority, int, which,
goto out_unlock; /* No processes for this user */
}
do_each_thread(g, p) {
- if (uid_eq(task_uid(p), uid))
+ if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
error = set_one_prio(p, niceval, error);
} while_each_thread(g, p);
if (!uid_eq(uid, cred->uid))
@@ -290,7 +290,7 @@ SYSCALL_DEFINE2(getpriority, int, which,
goto out_unlock; /* No processes for this user */
}
do_each_thread(g, p) {
- if (uid_eq(task_uid(p), uid)) {
+ if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
niceval = nice_to_rlimit(task_nice(p));
if (niceval > retval)
retval = niceval;
_
Patches currently in -mm which might be from bsegall@xxxxxxxxxx are
pidns-fix-set-getpriority-and-ioprio_set-get-in-prio_user-mode.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
