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 --- fs/namespace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index a67cbe42746d..eb7d2774ee1c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5678,13 +5678,16 @@ 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 (!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 * ns for the mount. This can happen if the mount is unmounted * with MNT_DETACH. */ s->mask &= ~(STATMOUNT_MNT_POINT | STATMOUNT_MNT_NS_ID); + } } else { /* Has the namespace already been emptied? */ if (mnt_ns_id && mnt_ns_empty(ns)) -- 2.34.1