nfsd: Return EPERM, not EACCES, in some SETATTR cases (255fbca6) · Commits · 戴 / test

As the man(2) page for utime/utimes states, EPERM is returned when the second parameter of utime or utimes is not NULL, the caller's effective UID does not match the owner of the file, and the caller is not privileged. However, in a NFS directory mounted from knfsd, it will return EACCES (from nfsd_setattr-> fh_verify->nfsd_permission). This patch fixes that. Signed-off-by:

zhengbin <zhengbin13@huawei.com> Signed-off-by:

J. Bruce Fields <bfields@redhat.com>

fs/nfsd/vfs.c

+15 −2

Original line number	Diff line number	Diff line
		@@ -396,10 +396,23 @@ nfsd_setattr(struct svc_rqst rqstp, struct svc_fh fhp, struct iattr *iap,
		bool get_write_count;
		bool size_change = (iap->ia_valid & ATTR_SIZE);

		if (iap->ia_valid & (ATTR_ATIME \| ATTR_MTIME \| ATTR_SIZE))
		if (iap->ia_valid & ATTR_SIZE) {
		accmode \|= NFSD_MAY_WRITE\|NFSD_MAY_OWNER_OVERRIDE;
		if (iap->ia_valid & ATTR_SIZE)
		ftype = S_IFREG;
		}

		/*
		* If utimes(2) and friends are called with times not NULL, we should
		* not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
		* will return EACCESS, when the caller's effective UID does not match
		* the owner of the file, and the caller is not privileged. In this
		* situation, we should return EPERM(notify_change will return this).
		*/
		if (iap->ia_valid & (ATTR_ATIME \| ATTR_MTIME)) {
		accmode \|= NFSD_MAY_OWNER_OVERRIDE;
		if (!(iap->ia_valid & (ATTR_ATIME_SET \| ATTR_MTIME_SET)))
		accmode \|= NFSD_MAY_WRITE;
		}

		/* Callers that do fh_verify should do the fh_want_write: */
		get_write_count = !fhp->fh_dentry;

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