From 52ee04330f585d1b5bc40442f07df07248fa3aee Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 20 Jun 2014 11:52:21 -0400 Subject: [PATCH] nfsd: let nfsd_symlink assume null-terminated data Currently nfsd_symlink has a weird hack to serve callers who don't null-terminate symlink data: it looks ahead at the next byte to see if it's zero, and copies it to a new buffer to null-terminate if not. That means callers don't have to null-terminate, but they *do* have to ensure that the byte following the end of the data is theirs to read. That's a bit subtle, and the NFSv4 code actually got this wrong. So let's just throw out that code and let callers pass null-terminated strings; we've already fixed them to do that. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs3proc.c | 2 +- fs/nfsd/nfs4proc.c | 2 +- fs/nfsd/nfsproc.c | 2 +- fs/nfsd/vfs.c | 17 +++-------------- fs/nfsd/vfs.h | 2 +- 5 files changed, 7 insertions(+), 18 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 61ef42c..19ba233 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -282,7 +282,7 @@ nfsd3_proc_symlink(struct svc_rqst *rqstp, struct nfsd3_symlinkargs *argp, fh_copy(&resp->dirfh, &argp->ffh); fh_init(&resp->fh, NFS3_FHSIZE); nfserr = nfsd_symlink(rqstp, &resp->dirfh, argp->fname, argp->flen, - argp->tname, argp->tlen, + argp->tname, &resp->fh, &argp->attrs); RETURN_STATUS(nfserr); } diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 2b3795a..7aa83bf 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -623,7 +623,7 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, case NF4LNK: status = nfsd_symlink(rqstp, &cstate->current_fh, create->cr_name, create->cr_namelen, - create->cr_linkname, create->cr_linklen, + create->cr_linkname, &resfh, &create->cr_iattr); break; diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index aebe23c..583ed03 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -409,7 +409,7 @@ nfsd_proc_symlink(struct svc_rqst *rqstp, struct nfsd_symlinkargs *argp, */ argp->tname[argp->tlen] = '\0'; nfserr = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen, - argp->tname, argp->tlen, + argp->tname, &newfh, &argp->attrs); diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 6ffaa70..7518c65 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1504,7 +1504,7 @@ out_nfserr: __be32 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *fname, int flen, - char *path, int plen, + char *path, struct svc_fh *resfhp, struct iattr *iap) { @@ -1513,7 +1513,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int host_err; err = nfserr_noent; - if (!flen || !plen) + if (!flen || path[0] == '\0') goto out; err = nfserr_exist; if (isdotent(fname, flen)) @@ -1534,18 +1534,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, if (IS_ERR(dnew)) goto out_nfserr; - if (unlikely(path[plen] != 0)) { - char *path_alloced = kmalloc(plen+1, GFP_KERNEL); - if (path_alloced == NULL) - host_err = -ENOMEM; - else { - strncpy(path_alloced, path, plen); - path_alloced[plen] = 0; - host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); - kfree(path_alloced); - } - } else - host_err = vfs_symlink(dentry->d_inode, dnew, path); + host_err = vfs_symlink(dentry->d_inode, dnew, path); err = nfserrno(host_err); if (!err) err = nfserrno(commit_metadata(fhp)); diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index b84aef5..20e4b66 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -85,7 +85,7 @@ __be32 nfsd_write(struct svc_rqst *, struct svc_fh *,struct file *, __be32 nfsd_readlink(struct svc_rqst *, struct svc_fh *, char *, int *); __be32 nfsd_symlink(struct svc_rqst *, struct svc_fh *, - char *name, int len, char *path, int plen, + char *name, int len, char *path, struct svc_fh *res, struct iattr *); __be32 nfsd_link(struct svc_rqst *, struct svc_fh *, char *, int, struct svc_fh *); -- 2.7.4