Commit 55725513 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Ensure that we check lock exclusive/shared type against open modes 



Since we may be simulating flock() locks using NFS byte range locks,
we can't rely on the VFS having checked the file open mode for us.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
parent 05ffe24f

fs/nfs/nfs4proc.c

+14 −0
Original line number Diff line number Diff line
@@ -4726,6 +4726,20 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) 


	if (state == NULL)

		return -ENOLCK;

	/*

	 * Don't rely on the VFS having checked the file open mode,

	 * since it won't do this for flock() locks.

	 */

	switch (request->fl_type & (F_RDLCK|F_WRLCK|F_UNLCK)) {

	case F_RDLCK:

		if (!(filp->f_mode & FMODE_READ))

			return -EBADF;

		break;

	case F_WRLCK:

		if (!(filp->f_mode & FMODE_WRITE))

			return -EBADF;

	}



	do {

		status = nfs4_proc_setlk(state, cmd, request);

		if ((status != -EAGAIN) || IS_SETLK(cmd))