From patchwork Thu May 31 17:01:19 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brad Figg X-Patchwork-Id: 162192 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 8C9B0B6FBA for ; Fri, 1 Jun 2012 03:01:38 +1000 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Sa8kc-0005mZ-Dh; Thu, 31 May 2012 17:01:30 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Sa8ka-0005lx-US for kernel-team@lists.ubuntu.com; Thu, 31 May 2012 17:01:28 +0000 Received: from static-50-53-107-235.bvtn.or.frontiernet.net ([50.53.107.235] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Sa8ka-0004Sh-Is for kernel-team@lists.ubuntu.com; Thu, 31 May 2012 17:01:28 +0000 From: Brad Figg To: kernel-team@lists.ubuntu.com Subject: [PATCH 2/3] [CVE-2012-2375] [ONEIRIC] [NATTY] Avoid beyond bounds copy while caching ACL Date: Thu, 31 May 2012 10:01:19 -0700 Message-Id: <1338483680-5668-3-git-send-email-brad.figg@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1338483680-5668-1-git-send-email-brad.figg@canonical.com> References: <1338483680-5668-1-git-send-email-brad.figg@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com From: Sachin Prabhu CVE-2012-2375 When attempting to cache ACLs returned from the server, if the bitmap size + the ACL size is greater than a PAGE_SIZE but the ACL size itself is smaller than a PAGE_SIZE, we can read past the buffer page boundary. Signed-off-by: Sachin Prabhu Reported-by: Jian Li Signed-off-by: Trond Myklebust (backported from commit 5794d21ef4639f0e33440927bb903f9598c21e92 upstream) Signed-off-by: Brad Figg --- fs/nfs/nfs4proc.c | 12 +++++------- fs/nfs/nfs4xdr.c | 2 +- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 5e2fa8a..2f8f3bb 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3514,16 +3514,16 @@ out: return ret; } -static void nfs4_write_cached_acl(struct inode *inode, const char *buf, size_t acl_len) +static void nfs4_write_cached_acl(struct inode *inode, struct page **pages, size_t pgbase, size_t acl_len) { struct nfs4_cached_acl *acl; - if (buf && acl_len <= PAGE_SIZE) { + if (pages && acl_len <= PAGE_SIZE) { acl = kmalloc(sizeof(*acl) + acl_len, GFP_KERNEL); if (acl == NULL) goto out; acl->cached = 1; - memcpy(acl->data, buf, acl_len); + _copy_from_pages(acl->data, pages, pgbase, acl_len); } else { acl = kmalloc(sizeof(*acl), GFP_KERNEL); if (acl == NULL) @@ -3556,7 +3556,6 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu struct nfs_getaclres res = { .acl_len = buflen, }; - void *resp_buf; struct rpc_message msg = { .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL], .rpc_argp = &args, @@ -3591,7 +3590,6 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu * the page we send as a guess */ if (buf == NULL) res.acl_flags |= NFS4_ACL_LEN_REQUEST; - resp_buf = page_address(pages[0]); dprintk("%s buf %p buflen %ld npages %d args.acl_len %ld\n", __func__, buf, buflen, npages, args.acl_len); @@ -3602,9 +3600,9 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu acl_len = res.acl_len - res.acl_data_offset; if (acl_len > args.acl_len) - nfs4_write_cached_acl(inode, NULL, acl_len); + nfs4_write_cached_acl(inode, NULL, 0, acl_len); else - nfs4_write_cached_acl(inode, resp_buf + res.acl_data_offset, + nfs4_write_cached_acl(inode, pages, res.acl_data_offset, acl_len); if (buf) { ret = -ERANGE; diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index e33f1e2..3e0b14e 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -4761,7 +4761,7 @@ static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req, res->acl_len = attrlen; goto out; } - dprintk("NFS: acl reply: attrlen %zu > page_len %u\n", + dprintk("NFS: acl reply: attrlen %u > page_len %zu\n", attrlen, page_len); return -EINVAL; }