[PATCH 5.10/6.1/6.12] mount: honour SB_NOUSER in the new mount API
Denis Arefev <[email protected]>
| Newsgroups | org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.stable |
|---|---|
| Message-ID | <[email protected]> |
From: Al Viro <[email protected]> commit 6dd3c6884cd9defb511284b566cef5ac8f657dbf upstream. One should *not* be allowed to mount one of those, new API or not. Reported-by: Denis Arefev <[email protected]> Signed-off-by: Al Viro <[email protected]> Link: https://patch.msgid.link/20260602020444.GP2636677@ZenIV Signed-off-by: Christian Brauner (Amutable) <[email protected]> [Denis: rename new_mnt -> newmount.mnt] [Denis: use goto err_unlock instead of direct return] Signed-off-by: Denis Arefev <[email protected]> --- fs/namespace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/namespace.c b/fs/namespace.c index 94c06c842902..a596381dba1c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -4229,6 +4229,11 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, ret = PTR_ERR(newmount.mnt); goto err_unlock; } + if (newmount.mnt->mnt_sb->s_flags & SB_NOUSER) { + mntput(newmount.mnt); + ret = -EINVAL; + goto err_unlock; + } newmount.dentry = dget(fc->root); newmount.mnt->mnt_flags = mnt_flags; -- 2.43.0