Date: Thu, 21 May 2015 23:14:18 +0000 (UTC) From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r283273 - head/sys/fs/nfsclient Message-ID: <201505212314.t4LNEIvO002650@svn.freebsd.org>
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Author: rmacklem Date: Thu May 21 23:14:18 2015 New Revision: 283273 URL: https://svnweb.freebsd.org/changeset/base/283273 Log: The NFS client wasn't handling getdirentries(2) requests for sizes that are not an exact multiple of DIRBLKSIZ correctly. Fortunately readdir(3) always uses an exact multiple of DIRBLKSIZ, so few applications were affected. This patch fixes this problem by reducing the size of the directory read to an exact multiple of DIRBLKSIZ. Tested by: trasz Reported by: trasz Reviewed by: trasz MFC after: 2 weeks Modified: head/sys/fs/nfsclient/nfs_clvnops.c Modified: head/sys/fs/nfsclient/nfs_clvnops.c ============================================================================== --- head/sys/fs/nfsclient/nfs_clvnops.c Thu May 21 22:50:39 2015 (r283272) +++ head/sys/fs/nfsclient/nfs_clvnops.c Thu May 21 23:14:18 2015 (r283273) @@ -2210,7 +2210,7 @@ nfs_readdir(struct vop_readdir_args *ap) struct vnode *vp = ap->a_vp; struct nfsnode *np = VTONFS(vp); struct uio *uio = ap->a_uio; - ssize_t tresid; + ssize_t tresid, left; int error = 0; struct vattr vattr; @@ -2239,6 +2239,17 @@ nfs_readdir(struct vop_readdir_args *ap) } /* + * NFS always guarantees that directory entries don't straddle + * DIRBLKSIZ boundaries. As such, we need to limit the size + * to an exact multiple of DIRBLKSIZ, to avoid copying a partial + * directory entry. + */ + left = uio->uio_resid % DIRBLKSIZ; + if (left == uio->uio_resid) + return (EINVAL); + uio->uio_resid -= left; + + /* * Call ncl_bioread() to do the real work. */ tresid = uio->uio_resid; @@ -2249,6 +2260,9 @@ nfs_readdir(struct vop_readdir_args *ap) if (ap->a_eofflag != NULL) *ap->a_eofflag = 1; } + + /* Add the partial DIRBLKSIZ (left) back in. */ + uio->uio_resid += left; return (error); }
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