This is a note to let you know that I've just added the patch titled
genirq/proc: Correctly set file permissions for affinity control files
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
genirq-proc-correctly-set-file-permissions-for-affin.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 94333b60d5d3d5d505da92fdcd965ef4b8e101ed
Author: Jeff Xie <jeff.xie@xxxxxxxxx>
Date: Sun Aug 25 21:19:11 2024 +0800
genirq/proc: Correctly set file permissions for affinity control files
[ Upstream commit c7718e5c76d49b5bb394265383ae51f766d5dd3a ]
The kernel already knows at the time of interrupt allocation whether
affinity of an interrupt can be controlled by userspace or not.
It still creates all related procfs control files with read/write
permissions. That's inconsistent and non-intuitive for system
administrators and tools.
Therefore set the file permissions to read-only for such interrupts.
[ tglx: Massage change log, fixed UP build ]
Signed-off-by: Jeff Xie <jeff.xie@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20240825131911.107119-1-jeff.xie@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index ee595ec09778d..b2893416c9df0 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -362,8 +362,13 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc)
goto out_unlock;
#ifdef CONFIG_SMP
+ umode_t umode = S_IRUGO;
+
+ if (irq_can_set_affinity_usr(desc->irq_data.irq))
+ umode |= S_IWUSR;
+
/* create /proc/irq/<irq>/smp_affinity */
- proc_create_data("smp_affinity", 0644, desc->dir,
+ proc_create_data("smp_affinity", umode, desc->dir,
&irq_affinity_proc_ops, irqp);
/* create /proc/irq/<irq>/affinity_hint */
@@ -371,7 +376,7 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc)
irq_affinity_hint_proc_show, irqp);
/* create /proc/irq/<irq>/smp_affinity_list */
- proc_create_data("smp_affinity_list", 0644, desc->dir,
+ proc_create_data("smp_affinity_list", umode, desc->dir,
&irq_affinity_list_proc_ops, irqp);
proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
