From 301f0268b63d1b07268e46f5901fc51d6cac20eb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 1 Sep 2013 16:06:39 -0400 Subject: [PATCH] nfsd: racy access to ->d_name in nsfd4_encode_path() Signed-off-by: Al Viro --- fs/nfsd/nfs4xdr.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index c2a4701..d9454fe 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1816,10 +1816,7 @@ static __be32 nfsd4_encode_fs_location4(struct nfsd4_fs_location *location, static __be32 nfsd4_encode_path(const struct path *root, const struct path *path, __be32 **pp, int *buflen) { - struct path cur = { - .mnt = path->mnt, - .dentry = path->dentry, - }; + struct path cur = *path; __be32 *p = *pp; struct dentry **components = NULL; unsigned int ncomponents = 0; @@ -1859,14 +1856,19 @@ static __be32 nfsd4_encode_path(const struct path *root, while (ncomponents) { struct dentry *dentry = components[ncomponents - 1]; - unsigned int len = dentry->d_name.len; + unsigned int len; + spin_lock(&dentry->d_lock); + len = dentry->d_name.len; *buflen -= 4 + (XDR_QUADLEN(len) << 2); - if (*buflen < 0) + if (*buflen < 0) { + spin_unlock(&dentry->d_lock); goto out_free; + } WRITE32(len); WRITEMEM(dentry->d_name.name, len); dprintk("/%s", dentry->d_name.name); + spin_unlock(&dentry->d_lock); dput(dentry); ncomponents--; } -- 2.7.4