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

[pandora-kernel.git] / fs / nfs / nfs4proc.c

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 57f9971..51f6a40 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4601,6 +4601,20 @@ 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))