[2/2] NFSv4: Handle the special Linux file open access mode
diff mbox series

Message ID 20190627161458.46784-2-trond.myklebust@hammerspace.com
State New
Headers show
Series
  • Untitled series #138957
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Commit Message

Trond Myklebust June 27, 2019, 4:14 p.m. UTC
According to the open() manpage, Linux reserves the access mode 3
to mean "check for read and write permission on the file and return
a file descriptor that can't be used for reading or writing."

Currently, the NFSv4 code will ask the server to open the file,
and will use an incorrect share access mode of 0. Since it has
an incorrect share access mode, the client later forgets to send
a corresponding close, meaning it can leak stateids on the server.

Fixes: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/inode.c    | 1 +
 fs/nfs/nfs4file.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

Patch
diff mbox series

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 0b4a1a974411..53777813ca95 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1100,6 +1100,7 @@  int nfs_open(struct inode *inode, struct file *filp)
 	nfs_fscache_open_file(inode, filp);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(nfs_open);
 
 /*
  * This function is called whenever some part of NFS notices that
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index cf42a8b939e3..3a507c42c1ca 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -49,7 +49,7 @@  nfs4_file_open(struct inode *inode, struct file *filp)
 		return err;
 
 	if ((openflags & O_ACCMODE) == 3)
-		openflags--;
+		return nfs_open(inode, filp);
 
 	/* We can't create new files here */
 	openflags &= ~(O_CREAT|O_EXCL);