From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Tejun Heo <tj@kernel.org>,
Abhishek Shah <abhishek.shah@columbia.edu>,
Gabriel Ryan <gabe@cs.columbia.edu>,
Christian Brauner <brauner@kernel.org>,
Sasha Levin <sashal@kernel.org>,
lizefan.x@bytedance.com, hannes@cmpxchg.org,
cgroups@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 05/21] cgroup: Remove data-race around cgrp_dfl_visible
Date: Mon, 17 Oct 2022 20:09:24 -0400 [thread overview]
Message-ID: <20221018000940.2731329-5-sashal@kernel.org> (raw)
In-Reply-To: <20221018000940.2731329-1-sashal@kernel.org>
From: Tejun Heo <tj@kernel.org>
[ Upstream commit dc79ec1b232ad2c165d381d3dd2626df4ef9b5a4 ]
There's a seemingly harmless data-race around cgrp_dfl_visible detected by
kernel concurrency sanitizer. Let's remove it by throwing WRITE/READ_ONCE at
it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Cc: Gabriel Ryan <gabe@cs.columbia.edu>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/netdev/20220819072256.fn7ctciefy4fc4cu@wittgenstein/
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/cgroup/cgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 4b19f7fc4deb..1dd45a1c1acc 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2152,7 +2152,7 @@ static int cgroup_get_tree(struct fs_context *fc)
struct cgroup_fs_context *ctx = cgroup_fc2context(fc);
int ret;
- cgrp_dfl_visible = true;
+ WRITE_ONCE(cgrp_dfl_visible, true);
cgroup_get_live(&cgrp_dfl_root.cgrp);
ctx->root = &cgrp_dfl_root;
@@ -6067,7 +6067,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct cgroup *cgrp;
int ssid, count = 0;
- if (root == &cgrp_dfl_root && !cgrp_dfl_visible)
+ if (root == &cgrp_dfl_root && !READ_ONCE(cgrp_dfl_visible))
continue;
seq_printf(m, "%d:", root->hierarchy_id);
--
2.35.1
next prev parent reply other threads:[~2022-10-18 0:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 0:09 [PATCH AUTOSEL 5.15 01/21] crypto: qcom-rng - Fix qcom_rng_of_match unused warning Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 02/21] crypto: ccp - Add a quirk to firmware update Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 03/21] gfs2: Switch from strlcpy to strscpy Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 04/21] powerpc/hw_breakpoint: Avoid relying on caller synchronization Sasha Levin
2022-10-18 0:09 ` Sasha Levin [this message]
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 06/21] of/fdt: Don't calculate initrd size from DT if start > end Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 07/21] objtool,x86: Teach decode about LOOP* instructions Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 08/21] locking/rwsem: Disable preemption while trying for rwsem lock Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 09/21] gfs2: Check sb_bsize_shift after reading superblock Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 10/21] powerpc/64: don't refer nr_cpu_ids in asm code when it's undefined Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 11/21] m68knommu: fix non-specific 68328 choice interrupt build failure Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 12/21] m68knommu: fix non-mmu classic 68000 legacy timer tick selection Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 13/21] of: Fix "dma-ranges" handling for bus controllers Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 14/21] x86/hyperv: Replace kmap() with kmap_local_page() Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 15/21] kmsan: disable instrumentation of unsupported common kernel code Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 16/21] kmsan: disable physical page merging in biovec Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 17/21] f2fs: fix to detect corrupted meta ino Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 18/21] 9p: trans_fd/p9_conn_cancel: drop client lock earlier Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 19/21] 9p/trans_fd: always use O_NONBLOCK read/write Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 20/21] net/9p: use a dedicated spinlock for trans_fd Sasha Levin
2022-10-18 0:09 ` [PATCH AUTOSEL 5.15 21/21] virtio_pci: don't try to use intxif pin is zero Sasha Levin
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