5.4-stable patches

added patches:
	cgroup-add-missing-cpus_read_lock-to-cgroup_attach_task_all.patch

diff --git a/queue-5.4/cgroup-add-missing-cpus_read_lock-to-cgroup_attach_task_all.patch b/queue-5.4/cgroup-add-missing-cpus_read_lock-to-cgroup_attach_task_all.patch
new file mode 100644 (file)
index 0000000..1dd9150
--- /dev/null
+++ b/queue-5.4/cgroup-add-missing-cpus_read_lock-to-cgroup_attach_task_all.patch
@@ -0,0 +1,51 @@
+From 43626dade36fa74d3329046f4ae2d7fdefe401c6 Mon Sep 17 00:00:00 2001
+From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
+Date: Thu, 25 Aug 2022 17:38:38 +0900
+Subject: cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all()
+
+From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
+
+commit 43626dade36fa74d3329046f4ae2d7fdefe401c6 upstream.
+
+syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at
+cpuset_attach() [1], for commit 4f7e7236435ca0ab ("cgroup: Fix
+threadgroup_rwsem <-> cpus_read_lock() deadlock") missed that
+cpuset_attach() is also called from cgroup_attach_task_all().
+Add cpus_read_lock() like what cgroup_procs_write_start() does.
+
+Link: https://syzkaller.appspot.com/bug?extid=29d3a3b4d86c8136ad9e [1]
+Reported-by: syzbot <syzbot+29d3a3b4d86c8136ad9e@syzkaller.appspotmail.com>
+Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
+Fixes: 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock")
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/cgroup/cgroup-v1.c |    3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/kernel/cgroup/cgroup-v1.c
++++ b/kernel/cgroup/cgroup-v1.c
+@@ -15,6 +15,7 @@
+ #include <linux/pid_namespace.h>
+ #include <linux/cgroupstats.h>
+ #include <linux/fs_parser.h>
++#include <linux/cpu.h>
+ 
+ #include <trace/events/cgroup.h>
+ 
+@@ -62,6 +63,7 @@ int cgroup_attach_task_all(struct task_s
+       int retval = 0;
+ 
+       mutex_lock(&cgroup_mutex);
++      cpus_read_lock();
+       percpu_down_write(&cgroup_threadgroup_rwsem);
+       for_each_root(root) {
+               struct cgroup *from_cgrp;
+@@ -78,6 +80,7 @@ int cgroup_attach_task_all(struct task_s
+                       break;
+       }
+       percpu_up_write(&cgroup_threadgroup_rwsem);
++      cpus_read_unlock();
+       mutex_unlock(&cgroup_mutex);
+ 
+       return retval;

diff --git a/queue-5.4/series b/queue-5.4/series
index 71d204d491488654de552967151d7de13e681ba2..bf07a58a088700e4d06bcdc488a9a4fad0cd6576 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -39,3 +39,4 @@ afs-return-eagain-not-eremoteio-when-a-file-already-.patch
 mips-octeon-irq-fix-octeon_irq_force_ciu_mapping.patch
 mksysmap-fix-the-mismatch-of-l0-symbols-in-system.ma.patch
 video-fbdev-pxa3xx-gcu-fix-integer-overflow-in-pxa3x.patch
+cgroup-add-missing-cpus_read_lock-to-cgroup_attach_task_all.patch