From: "Christian A. Ehrhardt" <lk@c--e.de>
To: Christian Brauner <brauner@kernel.org>
Cc: Tejun Heo <tj@kernel.org>,
syzbot <syzbot+534ee3d24c37c411f37f@syzkaller.appspotmail.com>,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
Yosry Ahmed <yosryahmed@google.com>
Subject: [PATCH] cgroup: Fix crash with CLONE_INTO_CGROUP and v1 cgroups
Date: Sun, 9 Oct 2022 15:10:36 +0200 [thread overview]
Message-ID: <Y0LITEA/22Z7YVSa@cae.in-ulm.de> (raw)
In-Reply-To: <20221009084039.cw6meqbvy4362lsa@wittgenstein>
Since commit f3a2aebdd6, Version 1 cgroups no longer cause an
error when used with CLONE_INTO_CGROUP. However, the permission
checks performed during clone assume a Version 2 cgroup.
Restore the error check for V1 cgroups in the clone() path.
Reported-by: syzbot+534ee3d24c37c411f37f@syzkaller.appspotmail.com
Link: https://lore.kernel.org/lkml/000000000000385cbf05ea3f1862@google.com/
Fixes: f3a2aebdd6 ("cgroup: enable cgroup_get_from_file() on cgroup1")
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
---
kernel/cgroup/cgroup.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b6e3110b3ea7..f7fc3afa88c1 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6244,6 +6244,11 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
goto err;
}
+ if (!cgroup_on_dfl(dst_cgrp)) {
+ ret = -EBADF;
+ goto err;
+ }
+
if (cgroup_is_dead(dst_cgrp)) {
ret = -ENODEV;
goto err;
--
2.34.1
next prev parent reply other threads:[~2022-10-09 13:10 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-05 0:59 [syzbot] general protection fault in kernfs_get_inode syzbot
2022-10-05 2:19 ` syzbot
2022-10-07 21:35 ` Tejun Heo
2022-10-08 5:46 ` Christian Brauner
2022-10-08 5:51 ` Christian Brauner
2022-10-08 11:15 ` syzbot
2022-10-08 18:29 ` Christian A. Ehrhardt
2022-10-09 8:42 ` Christian Brauner
2022-10-09 13:10 ` Christian A. Ehrhardt [this message]
2022-10-09 17:35 ` [PATCH] cgroup: Fix crash with CLONE_INTO_CGROUP and v1 cgroups Christian Brauner
2022-10-09 18:16 ` Greg KH
2022-10-10 18:48 ` Tejun Heo
2022-10-09 18:42 ` Yosry Ahmed
2022-10-10 18:38 ` Martin KaFai Lau
2022-10-10 18:43 ` Tejun Heo
2022-10-10 18:50 ` Yosry Ahmed
2022-10-10 19:51 ` Tejun Heo
2022-10-10 19:57 ` Yosry Ahmed
2022-10-10 20:07 ` Tejun Heo
2022-10-10 20:09 ` Yosry Ahmed
2022-11-17 7:26 ` [syzbot] general protection fault in kernfs_get_inode syzbot
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