From: Qian Cai <cai@lca.pw>
To: tj@kernel.org
Cc: lizefan@huawei.com, hannes@cmpxchg.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH] cgroup: fix psi_show() crash on 32bit ino archs
Date: Sun, 23 Feb 2020 22:00:07 -0500 [thread overview]
Message-ID: <20200224030007.3990-1-cai@lca.pw> (raw)
Similar to the commit d7495343228f ("cgroup: fix incorrect
WARN_ON_ONCE() in cgroup_setup_root()"), cgroup_id(root_cgrp) does not
equal to 1 on 32bit ino archs which triggers all sorts of issues with
psi_show() on s390x. For example,
BUG: KASAN: slab-out-of-bounds in collect_percpu_times+0x2d0/
Read of size 4 at addr 000000001e0ce000 by task read_all/3667
collect_percpu_times+0x2d0/0x798
psi_show+0x7c/0x2a8
seq_read+0x2ac/0x830
vfs_read+0x92/0x150
ksys_read+0xe2/0x188
system_call+0xd8/0x2b4
Fix it by using cgroup_ino().
Fixes: 743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID")
Signed-off-by: Qian Cai <cai@lca.pw>
---
kernel/cgroup/cgroup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 75f687301bbf..cd5f41289f7d 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3542,21 +3542,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_IO);
}
static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_MEM);
}
static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
+ struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_CPU);
}
--
2.21.0 (Apple Git-122.2)
next reply other threads:[~2020-02-24 3:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 3:00 Qian Cai [this message]
2020-02-24 16:29 ` [PATCH] cgroup: fix psi_show() crash on 32bit ino archs Johannes Weiner
2020-03-04 13:36 ` Qian Cai
2020-03-04 16:16 ` Tejun Heo
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