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Date:   Mon, 13 Jul 2020 14:57:59 -0700
Message-Id: <20200713215759.3701482-1-victorhsieh@google.com>
Mime-Version: 1.0
Subject: [PATCH] fs/9p: Fix TCREATE's fid in protocol
From:   Victor Hsieh <victorhsieh@google.com>
To:     v9fs-developer@lists.sourceforge.net,
        Eric Van Hensbergen <ericvh@gmail.com>,
        Latchesar Ionkov <lucho@ionkov.net>,
        Dominique Martinet <asmadeus@codewreck.org>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Victor Hsieh <victorhsieh@google.com>, stable@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The fid parameter of TCREATE represents the directory that the file
should be created at. The current implementation mistakenly passes a
locally created fid for the file. The correct file fid is usually
retrieved by another WALK call, which does happen right after.

The problem happens when a new created fd is read from (i.e. where
private_data->fid is used), but not write to.

Fixes: 5643135a2846 ("fs/9p: This patch implements TLCREATE for 9p2000.L protocol.")
Signed-off-by: Victor Hsieh <victorhsieh@google.com>
Cc: stable@vger.kernel.org
---
 fs/9p/vfs_inode_dotl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 60328b21c5fb..90a7aaea918d 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -285,7 +285,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 			 err);
 		goto error;
 	}
-	err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
+	err = p9_client_create_dotl(dfid, name, v9fs_open_to_dotl_flags(flags),
 				    mode, gid, &qid);
 	if (err < 0) {
 		p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
-- 
2.27.0.383.g050319c2ae-goog