* [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
@ 2021-04-02 2:58 Josh Hunt
2021-04-02 17:53 ` Johannes Weiner
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Josh Hunt @ 2021-04-02 2:58 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, linux-kernel, ebiederm, keescook, hannes
Cc: Josh Hunt
Currently only root can write files under /proc/pressure. Relax this to
allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be
able to write to these files.
Signed-off-by: Josh Hunt <johunt@akamai.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
kernel/sched/psi.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index b1b00e9bd7ed..d1212f17a898 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1061,19 +1061,27 @@ static int psi_cpu_show(struct seq_file *m, void *v)
return psi_show(m, &psi_system, PSI_CPU);
}
+static int psi_open(struct file *file, int (*psi_show)(struct seq_file *, void *))
+{
+ if (file->f_mode & FMODE_WRITE && !capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ return single_open(file, psi_show, NULL);
+}
+
static int psi_io_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_io_show, NULL);
+ return psi_open(file, psi_io_show);
}
static int psi_memory_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_memory_show, NULL);
+ return psi_open(file, psi_memory_show);
}
static int psi_cpu_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_cpu_show, NULL);
+ return psi_open(file, psi_cpu_show);
}
struct psi_trigger *psi_trigger_create(struct psi_group *group,
@@ -1353,9 +1361,9 @@ static int __init psi_proc_init(void)
{
if (psi_enable) {
proc_mkdir("pressure", NULL);
- proc_create("pressure/io", 0, NULL, &psi_io_proc_ops);
- proc_create("pressure/memory", 0, NULL, &psi_memory_proc_ops);
- proc_create("pressure/cpu", 0, NULL, &psi_cpu_proc_ops);
+ proc_create("pressure/io", 0666, NULL, &psi_io_proc_ops);
+ proc_create("pressure/memory", 0666, NULL, &psi_memory_proc_ops);
+ proc_create("pressure/cpu", 0666, NULL, &psi_cpu_proc_ops);
}
return 0;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
2021-04-02 2:58 [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Josh Hunt
@ 2021-04-02 17:53 ` Johannes Weiner
2021-04-02 18:11 ` Kees Cook
2021-04-09 11:24 ` [tip: sched/core] " tip-bot2 for Josh Hunt
2 siblings, 0 replies; 4+ messages in thread
From: Johannes Weiner @ 2021-04-02 17:53 UTC (permalink / raw)
To: Josh Hunt; +Cc: Ingo Molnar, Peter Zijlstra, linux-kernel, ebiederm, keescook
On Thu, Apr 01, 2021 at 10:58:33PM -0400, Josh Hunt wrote:
> Currently only root can write files under /proc/pressure. Relax this to
> allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be
> able to write to these files.
>
> Signed-off-by: Josh Hunt <johunt@akamai.com>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
v2 looks good to me. Thanks
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
2021-04-02 2:58 [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Josh Hunt
2021-04-02 17:53 ` Johannes Weiner
@ 2021-04-02 18:11 ` Kees Cook
2021-04-09 11:24 ` [tip: sched/core] " tip-bot2 for Josh Hunt
2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2021-04-02 18:11 UTC (permalink / raw)
To: Josh Hunt; +Cc: Ingo Molnar, Peter Zijlstra, linux-kernel, ebiederm, hannes
On Thu, Apr 01, 2021 at 10:58:33PM -0400, Josh Hunt wrote:
> Currently only root can write files under /proc/pressure. Relax this to
> allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be
> able to write to these files.
>
> Signed-off-by: Josh Hunt <johunt@akamai.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip: sched/core] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
2021-04-02 2:58 [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Josh Hunt
2021-04-02 17:53 ` Johannes Weiner
2021-04-02 18:11 ` Kees Cook
@ 2021-04-09 11:24 ` tip-bot2 for Josh Hunt
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot2 for Josh Hunt @ 2021-04-09 11:24 UTC (permalink / raw)
To: linux-tip-commits
Cc: Josh Hunt, Peter Zijlstra (Intel), Johannes Weiner, x86, linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 6db12ee0456d0e369c7b59788d46e15a56ad0294
Gitweb: https://git.kernel.org/tip/6db12ee0456d0e369c7b59788d46e15a56ad0294
Author: Josh Hunt <johunt@akamai.com>
AuthorDate: Thu, 01 Apr 2021 22:58:33 -04:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 08 Apr 2021 23:09:44 +02:00
psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
Currently only root can write files under /proc/pressure. Relax this to
allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be
able to write to these files.
Signed-off-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20210402025833.27599-1-johunt@akamai.com
---
kernel/sched/psi.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index b1b00e9..d1212f1 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1061,19 +1061,27 @@ static int psi_cpu_show(struct seq_file *m, void *v)
return psi_show(m, &psi_system, PSI_CPU);
}
+static int psi_open(struct file *file, int (*psi_show)(struct seq_file *, void *))
+{
+ if (file->f_mode & FMODE_WRITE && !capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ return single_open(file, psi_show, NULL);
+}
+
static int psi_io_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_io_show, NULL);
+ return psi_open(file, psi_io_show);
}
static int psi_memory_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_memory_show, NULL);
+ return psi_open(file, psi_memory_show);
}
static int psi_cpu_open(struct inode *inode, struct file *file)
{
- return single_open(file, psi_cpu_show, NULL);
+ return psi_open(file, psi_cpu_show);
}
struct psi_trigger *psi_trigger_create(struct psi_group *group,
@@ -1353,9 +1361,9 @@ static int __init psi_proc_init(void)
{
if (psi_enable) {
proc_mkdir("pressure", NULL);
- proc_create("pressure/io", 0, NULL, &psi_io_proc_ops);
- proc_create("pressure/memory", 0, NULL, &psi_memory_proc_ops);
- proc_create("pressure/cpu", 0, NULL, &psi_cpu_proc_ops);
+ proc_create("pressure/io", 0666, NULL, &psi_io_proc_ops);
+ proc_create("pressure/memory", 0666, NULL, &psi_memory_proc_ops);
+ proc_create("pressure/cpu", 0666, NULL, &psi_cpu_proc_ops);
}
return 0;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-04-09 11:24 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-04-02 2:58 [PATCH v2] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Josh Hunt
2021-04-02 17:53 ` Johannes Weiner
2021-04-02 18:11 ` Kees Cook
2021-04-09 11:24 ` [tip: sched/core] " tip-bot2 for Josh Hunt
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