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From: Eugene Syromiatnikov <esyr@redhat.com>
To: linux-kernel@vger.kernel.org, Christian Brauner <christian@brauner.io>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>, Tejun Heo <tj@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"Dmitry V. Levin" <ldv@altlinux.org>
Subject: [PATCH] clone3: add a check for the user struct size if CLONE_INTO_CGROUP is set
Date: Sun, 12 Apr 2020 22:31:23 +0200	[thread overview]
Message-ID: <20200412203123.GA5869@asgard.redhat.com> (raw)

Passing CLONE_INTO_CGROUP with an under-sized structure (that doesn't
properly contain cgroup field) seems like garbage input, especially
considering the fact that fd 0 is a valid descriptor.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
---
 kernel/fork.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 11bcc7e..8c700f8 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2639,7 +2639,8 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
 		     !valid_signal(args.exit_signal)))
 		return -EINVAL;
 
-	if ((args.flags & CLONE_INTO_CGROUP) && args.cgroup > INT_MAX)
+	if ((args.flags & CLONE_INTO_CGROUP) &&
+	    (args.cgroup > INT_MAX || usize < CLONE_ARGS_SIZE_VER2))
 		return -EINVAL;
 
 	*kargs = (struct kernel_clone_args){
-- 
2.1.4


             reply	other threads:[~2020-04-12 20:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-12 20:31 Eugene Syromiatnikov [this message]
2020-04-12 21:13 ` Christian Brauner
2020-04-15 12:39 ` Christian Brauner

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