This patch is intended to go on top of "nfsd: return -EINVAL when namelen is 0" from Li Lingfeng. Li's patch checks for 0, but we should be enforcing an upper bound as well. Note that if nfsdcld somehow gets an id > NFS4_OPAQUE_LIMIT in its database, it'll truncate it to NFS4_OPAQUE_LIMIT when it does the downcall anyway. Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx> --- fs/nfsd/nfs4recover.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 69a3a84e159e..a2b995ee77f4 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -809,8 +809,8 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg, ci = &cmsg->cm_u.cm_clntinfo; if (get_user(namelen, &ci->cc_name.cn_len)) return -EFAULT; - if (!namelen) { - dprintk("%s: namelen should not be zero", __func__); + if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) { + dprintk("%s: invalid namelen (%u)", __func__, namelen); return -EINVAL; } name.data = memdup_user(&ci->cc_name.cn_id, namelen); @@ -835,8 +835,8 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg, cnm = &cmsg->cm_u.cm_name; if (get_user(namelen, &cnm->cn_len)) return -EFAULT; - if (!namelen) { - dprintk("%s: namelen should not be zero", __func__); + if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) { + dprintk("%s: invalid namelen (%u)", __func__, namelen); return -EINVAL; } name.data = memdup_user(&cnm->cn_id, namelen); -- 2.46.0