From: Trond Myklebust <Trond.Myklebust(a)netapp.com>
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: Trond Myklebust <Trond.Myklebust(a)netapp.com>
Cc: stable(a)vger.kernel.org
---
fs/nfs/nfs4proc.c | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c3f1715..1515e45 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4608,6 +4608,20 @@ 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))
--
1.7.7.6