From 81f16c9778d730f573d0d565706bb7227e2405f4 Mon Sep 17 00:00:00 2001 From: Qing Wang Date: Fri, 13 Feb 2026 18:30:06 +0800 Subject: [PATCH] statmount: Fix the null-ptr-deref in do_statmount() If the mount is internal, it's mnt_ns will be MNT_NS_INTERNAL, which is defined as ERR_PTR(-EINVAL). So, in the do_statmount(), need to check ns of mount by IS_ERR() and return. Fixes: 0e5032237ee5 ("statmount: accept fd as a parameter") Reported-by: syzbot+9e03a9535ea65f687a44@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/698e287a.a70a0220.2c38d7.009e.GAE@google.com/ Signed-off-by: Qing Wang Link: https://patch.msgid.link/20260213103006.2472569-1-wangqing7171@gmail.com Reviewed-by: Bhavik Sachdev Signed-off-by: Christian Brauner --- fs/namespace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/namespace.c b/fs/namespace.c index a67cbe42746d..90700df65f0d 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5678,6 +5678,8 @@ static int do_statmount(struct kstatmount *s, u64 mnt_id, u64 mnt_ns_id, s->mnt = mnt_file->f_path.mnt; ns = real_mount(s->mnt)->mnt_ns; + if (IS_ERR(ns)) + return PTR_ERR(ns); if (!ns) /* * We can't set mount point and mnt_ns_id since we don't have a