Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753265AbaGZTTc (ORCPT ); Sat, 26 Jul 2014 15:19:32 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34338 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754239AbaGZTN0 (ORCPT ); Sat, 26 Jul 2014 15:13:26 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Borkmann , "David S. Miller" Subject: [PATCH 3.15 037/109] net: sctp: propagate sysctl errors from proc_do* properly Date: Sat, 26 Jul 2014 12:01:59 -0700 Message-Id: <20140726190224.957440754@linuxfoundation.org> X-Mailer: git-send-email 2.0.2 In-Reply-To: <20140726190223.834037485@linuxfoundation.org> References: <20140726190223.834037485@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann [ Upstream commit ff5e92c1affe7166b3f6e7073e648ed65a6e2e59 ] sysctl handler proc_sctp_do_hmac_alg(), proc_sctp_do_rto_min() and proc_sctp_do_rto_max() do not properly reflect some error cases when writing values via sysctl from internal proc functions such as proc_dointvec() and proc_dostring(). In all these cases we pass the test for write != 0 and partially do additional work just to notice that additional sanity checks fail and we return with hard-coded -EINVAL while proc_do* functions might also return different errors. So fix this up by simply testing a successful return of proc_do* right after calling it. This also allows to propagate its return value onwards to the user. While touching this, also fix up some minor style issues. Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl") Fixes: 3c68198e7511 ("sctp: Make hmac algorithm selection for cookie generation dynamic") Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/sysctl.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -307,41 +307,40 @@ static int proc_sctp_do_hmac_alg(struct loff_t *ppos) { struct net *net = current->nsproxy->net_ns; - char tmp[8]; struct ctl_table tbl; - int ret; - int changed = 0; + bool changed = false; char *none = "none"; + char tmp[8]; + int ret; memset(&tbl, 0, sizeof(struct ctl_table)); if (write) { tbl.data = tmp; - tbl.maxlen = 8; + tbl.maxlen = sizeof(tmp); } else { tbl.data = net->sctp.sctp_hmac_alg ? : none; tbl.maxlen = strlen(tbl.data); } - ret = proc_dostring(&tbl, write, buffer, lenp, ppos); - if (write) { + ret = proc_dostring(&tbl, write, buffer, lenp, ppos); + if (write && ret == 0) { #ifdef CONFIG_CRYPTO_MD5 if (!strncmp(tmp, "md5", 3)) { net->sctp.sctp_hmac_alg = "md5"; - changed = 1; + changed = true; } #endif #ifdef CONFIG_CRYPTO_SHA1 if (!strncmp(tmp, "sha1", 4)) { net->sctp.sctp_hmac_alg = "sha1"; - changed = 1; + changed = true; } #endif if (!strncmp(tmp, "none", 4)) { net->sctp.sctp_hmac_alg = NULL; - changed = 1; + changed = true; } - if (!changed) ret = -EINVAL; } @@ -354,11 +353,10 @@ static int proc_sctp_do_rto_min(struct c loff_t *ppos) { struct net *net = current->nsproxy->net_ns; - int new_value; - struct ctl_table tbl; unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; - int ret; + struct ctl_table tbl; + int ret, new_value; memset(&tbl, 0, sizeof(struct ctl_table)); tbl.maxlen = sizeof(unsigned int); @@ -367,12 +365,15 @@ static int proc_sctp_do_rto_min(struct c tbl.data = &new_value; else tbl.data = &net->sctp.rto_min; + ret = proc_dointvec(&tbl, write, buffer, lenp, ppos); - if (write) { - if (ret || new_value > max || new_value < min) + if (write && ret == 0) { + if (new_value > max || new_value < min) return -EINVAL; + net->sctp.rto_min = new_value; } + return ret; } @@ -381,11 +382,10 @@ static int proc_sctp_do_rto_max(struct c loff_t *ppos) { struct net *net = current->nsproxy->net_ns; - int new_value; - struct ctl_table tbl; unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; - int ret; + struct ctl_table tbl; + int ret, new_value; memset(&tbl, 0, sizeof(struct ctl_table)); tbl.maxlen = sizeof(unsigned int); @@ -394,12 +394,15 @@ static int proc_sctp_do_rto_max(struct c tbl.data = &new_value; else tbl.data = &net->sctp.rto_max; + ret = proc_dointvec(&tbl, write, buffer, lenp, ppos); - if (write) { - if (ret || new_value > max || new_value < min) + if (write && ret == 0) { + if (new_value > max || new_value < min) return -EINVAL; + net->sctp.rto_max = new_value; } + return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/