From fcfa447062b2061e11f68b846d61cbfe60d0d604 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Fri, 10 Nov 2017 06:27:49 -0500 Subject: NFS: Revert "NFS: Move the flock open mode check into nfs_flock()" Commit e12937279c8b "NFS: Move the flock open mode check into nfs_flock()" changed NFSv3 behavior for flock() such that the open mode must match the lock type, however that requirement shouldn't be enforced for flock(). Signed-off-by: Benjamin Coddington Cc: stable@vger.kernel.org # v4.12 Signed-off-by: Anna Schumaker --- fs/nfs/nfs4proc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'fs/nfs/nfs4proc.c') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 6b23a032ee1e..56fa5a16e097 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6709,6 +6709,20 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) !test_bit(NFS_STATE_POSIX_LOCKS, &state->flags)) 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) { + case F_RDLCK: + if (!(filp->f_mode & FMODE_READ)) + return -EBADF; + break; + case F_WRLCK: + if (!(filp->f_mode & FMODE_WRITE)) + return -EBADF; + } + status = nfs4_set_lock_state(state, request); if (status != 0) return status; -- cgit v1.2.3