Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583AbaG3Mjg (ORCPT ); Wed, 30 Jul 2014 08:39:36 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:36679 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752802AbaG3MP1 (ORCPT ); Wed, 30 Jul 2014 08:15:27 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Daniel Borkmann , "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 33/94] net: sctp: propagate sysctl errors from proc_do* properly Date: Wed, 30 Jul 2014 14:14:22 +0200 Message-Id: X-Mailer: git-send-email 2.0.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Borkmann 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ 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: Jiri Slaby --- net/sctp/sysctl.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 3e5ac1948607..976c89d5295b 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -303,41 +303,40 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, 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; } -- 2.0.1 -- 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/