From 686a816ab6bedb99a892f3171f6c9ccecabff180 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 19 Feb 2017 16:08:32 -0500 Subject: NFSv4: Clean up owner/group attribute decode Signed-off-by: Trond Myklebust Reviewed-by: Chuck Lever Signed-off-by: Anna Schumaker --- fs/nfs/nfs4xdr.c | 117 +++++++++++++++++++++++++++---------------------------- 1 file changed, 57 insertions(+), 60 deletions(-) diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index ec0d76712e43..3268a2393512 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -3875,45 +3875,50 @@ out_overflow: return -EIO; } +static ssize_t decode_nfs4_string(struct xdr_stream *xdr, + struct nfs4_string *name, gfp_t gfp_flags) +{ + ssize_t ret; + + ret = xdr_stream_decode_string_dup(xdr, &name->data, + XDR_MAX_NETOBJ, gfp_flags); + name->len = 0; + if (ret > 0) + name->len = ret; + return ret; +} + static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap, const struct nfs_server *server, kuid_t *uid, struct nfs4_string *owner_name) { - uint32_t len; - __be32 *p; - int ret = 0; + ssize_t len; + char *p; *uid = make_kuid(&init_user_ns, -2); if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER - 1U))) return -EIO; - if (likely(bitmap[1] & FATTR4_WORD1_OWNER)) { - p = xdr_inline_decode(xdr, 4); - if (unlikely(!p)) - goto out_overflow; - len = be32_to_cpup(p); - p = xdr_inline_decode(xdr, len); - if (unlikely(!p)) - goto out_overflow; - if (owner_name != NULL) { - owner_name->data = kmemdup(p, len, GFP_NOWAIT); - if (owner_name->data != NULL) { - owner_name->len = len; - ret = NFS_ATTR_FATTR_OWNER_NAME; - } - } else if (len < XDR_MAX_NETOBJ) { - if (nfs_map_name_to_uid(server, (char *)p, len, uid) == 0) - ret = NFS_ATTR_FATTR_OWNER; - else - dprintk("%s: nfs_map_name_to_uid failed!\n", - __func__); - } else - dprintk("%s: name too long (%u)!\n", - __func__, len); - bitmap[1] &= ~FATTR4_WORD1_OWNER; + if (!(bitmap[1] & FATTR4_WORD1_OWNER)) + return 0; + bitmap[1] &= ~FATTR4_WORD1_OWNER; + + if (owner_name != NULL) { + len = decode_nfs4_string(xdr, owner_name, GFP_NOWAIT); + if (len <= 0) + goto out; + dprintk("%s: name=%s\n", __func__, owner_name->data); + return NFS_ATTR_FATTR_OWNER_NAME; + } else { + len = xdr_stream_decode_opaque_inline(xdr, (void **)&p, + XDR_MAX_NETOBJ); + if (len <= 0 || nfs_map_name_to_uid(server, p, len, uid) != 0) + goto out; + dprintk("%s: uid=%d\n", __func__, (int)from_kuid(&init_user_ns, *uid)); + return NFS_ATTR_FATTR_OWNER; } - dprintk("%s: uid=%d\n", __func__, (int)from_kuid(&init_user_ns, *uid)); - return ret; -out_overflow: +out: + if (len != -EBADMSG) + return 0; print_overflow_msg(__func__, xdr); return -EIO; } @@ -3922,41 +3927,33 @@ static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap, const struct nfs_server *server, kgid_t *gid, struct nfs4_string *group_name) { - uint32_t len; - __be32 *p; - int ret = 0; + ssize_t len; + char *p; *gid = make_kgid(&init_user_ns, -2); if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER_GROUP - 1U))) return -EIO; - if (likely(bitmap[1] & FATTR4_WORD1_OWNER_GROUP)) { - p = xdr_inline_decode(xdr, 4); - if (unlikely(!p)) - goto out_overflow; - len = be32_to_cpup(p); - p = xdr_inline_decode(xdr, len); - if (unlikely(!p)) - goto out_overflow; - if (group_name != NULL) { - group_name->data = kmemdup(p, len, GFP_NOWAIT); - if (group_name->data != NULL) { - group_name->len = len; - ret = NFS_ATTR_FATTR_GROUP_NAME; - } - } else if (len < XDR_MAX_NETOBJ) { - if (nfs_map_group_to_gid(server, (char *)p, len, gid) == 0) - ret = NFS_ATTR_FATTR_GROUP; - else - dprintk("%s: nfs_map_group_to_gid failed!\n", - __func__); - } else - dprintk("%s: name too long (%u)!\n", - __func__, len); - bitmap[1] &= ~FATTR4_WORD1_OWNER_GROUP; + if (!(bitmap[1] & FATTR4_WORD1_OWNER_GROUP)) + return 0; + bitmap[1] &= ~FATTR4_WORD1_OWNER_GROUP; + + if (group_name != NULL) { + len = decode_nfs4_string(xdr, group_name, GFP_NOWAIT); + if (len <= 0) + goto out; + dprintk("%s: name=%s\n", __func__, group_name->data); + return NFS_ATTR_FATTR_OWNER_NAME; + } else { + len = xdr_stream_decode_opaque_inline(xdr, (void **)&p, + XDR_MAX_NETOBJ); + if (len <= 0 || nfs_map_group_to_gid(server, p, len, gid) != 0) + goto out; + dprintk("%s: gid=%d\n", __func__, (int)from_kgid(&init_user_ns, *gid)); + return NFS_ATTR_FATTR_GROUP; } - dprintk("%s: gid=%d\n", __func__, (int)from_kgid(&init_user_ns, *gid)); - return ret; -out_overflow: +out: + if (len != -EBADMSG) + return 0; print_overflow_msg(__func__, xdr); return -EIO; } -- cgit v1.2.3