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authorQian Cai <cai@lca.pw>2020-02-23 22:00:07 -0500
committerTejun Heo <tj@kernel.org>2020-03-04 11:15:58 -0500
commit190ecb190a9cd8c0599d8499b901e3c32e87966a (patch)
tree2893bb1920caa0d2912bc1bdc415333f4ce3aad0 /kernel/cgroup
parent9c974c77246460fa6a92c18554c3311c8c83c160 (diff)
downloadlwn-190ecb190a9cd8c0599d8499b901e3c32e87966a.tar.gz
lwn-190ecb190a9cd8c0599d8499b901e3c32e87966a.zip
cgroup: fix psi_show() crash on 32bit ino archs
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> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # v5.5
Diffstat (limited to 'kernel/cgroup')
-rw-r--r--kernel/cgroup/cgroup.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index c719a4154d6d..7a39dc882095 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);
}