From 6fa02839bf9412e18e773d04e96182b4cd0b5d57 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 12 Nov 2007 16:05:03 -0500 Subject: [PATCH] nfsd4: recheck for secure ports in fh_verify As with commit 7fc90ec93a5eb71f4b08403baf5ba7176b3ec6b1 ("knfsd: nfsd: call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem") this is a case where we need to redo a security check in fh_verify() even though the filehandle already has an associated dentry--if the filehandle was created by fh_compose() in an earlier operation of the nfsv4 compound, then we may not have done these checks yet. Without this fix it is possible, for example, to traverse from an export without the secure ports requirement to one with it in a single compound, and bypass the secure port check on the new export. While we're here, fix up some minor style problems and change a printk() to a dprintk(), to make it harder for random unprivileged users to spam the logs. Signed-off-by: J. Bruce Fields Reviewed-By: NeilBrown Signed-off-by: Linus Torvalds --- fs/nfsd/nfsfh.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index 4f712e970584..468f17a78441 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -95,6 +95,22 @@ nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type) return 0; } +static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp, + struct svc_export *exp) +{ + /* Check if the request originated from a secure port. */ + if (!rqstp->rq_secure && EX_SECURE(exp)) { + char buf[RPC_MAX_ADDRBUFLEN]; + dprintk(KERN_WARNING + "nfsd: request from insecure port %s!\n", + svc_print_addr(rqstp, buf, sizeof(buf))); + return nfserr_perm; + } + + /* Set user creds for this exportpoint */ + return nfserrno(nfsd_setuser(rqstp, exp)); +} + /* * Perform sanity checks on the dentry in a client's file handle. * @@ -167,18 +183,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) goto out; } - /* Check if the request originated from a secure port. */ - error = nfserr_perm; - if (!rqstp->rq_secure && EX_SECURE(exp)) { - char buf[RPC_MAX_ADDRBUFLEN]; - printk(KERN_WARNING - "nfsd: request from insecure port %s!\n", - svc_print_addr(rqstp, buf, sizeof(buf))); - goto out; - } - - /* Set user creds for this exportpoint */ - error = nfserrno(nfsd_setuser(rqstp, exp)); + error = nfsd_setuser_and_check_port(rqstp, exp); if (error) goto out; @@ -227,18 +232,22 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) fhp->fh_export = exp; nfsd_nr_verified++; } else { - /* just rechecking permissions - * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well) + /* + * just rechecking permissions + * (e.g. nfsproc_create calls fh_verify, then nfsd_create + * does as well) */ dprintk("nfsd: fh_verify - just checking\n"); dentry = fhp->fh_dentry; exp = fhp->fh_export; - /* Set user creds for this exportpoint; necessary even + /* + * Set user creds for this exportpoint; necessary even * in the "just checking" case because this may be a * filehandle that was created by fh_compose, and that * is about to be used in another nfsv4 compound - * operation */ - error = nfserrno(nfsd_setuser(rqstp, exp)); + * operation. + */ + error = nfsd_setuser_and_check_port(rqstp, exp); if (error) goto out; } -- 2.34.1