From 318debd897735fe834545b6f3d2e96bcc9210b9f Mon Sep 17 00:00:00 2001 From: "nikolay@redhat.com" Date: Sat, 18 May 2013 01:18:31 +0000 Subject: [PATCH] bonding: fix multiple 3ad mode sysfs race conditions When bond_3ad_get_active_agg_info() is used in all show_ad_ functions it is not protected against slave manipulation and since it walks over the slaves and uses them, this can easily result in NULL pointer dereference or use of freed memory. Both the new wrapper and the internal function are exported to the bonding as they're needed in different places. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- drivers/net/bonding/bond_3ad.c | 21 +++++++++++++++++---- drivers/net/bonding/bond_3ad.h | 2 ++ drivers/net/bonding/bond_procfs.c | 2 +- drivers/net/bonding/bond_sysfs.c | 9 ++++----- 4 files changed, 24 insertions(+), 10 deletions(-) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index fc58d11..390061d 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -2360,14 +2360,15 @@ int bond_3ad_set_carrier(struct bonding *bond) } /** - * bond_3ad_get_active_agg_info - get information of the active aggregator + * __bond_3ad_get_active_agg_info - get information of the active aggregator * @bond: bonding struct to work on * @ad_info: ad_info struct to fill with the bond's info * * Returns: 0 on success * < 0 on error */ -int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info) +int __bond_3ad_get_active_agg_info(struct bonding *bond, + struct ad_info *ad_info) { struct aggregator *aggregator = NULL; struct port *port; @@ -2391,6 +2392,18 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info) return -1; } +/* Wrapper used to hold bond->lock so no slave manipulation can occur */ +int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info) +{ + int ret; + + read_lock(&bond->lock); + ret = __bond_3ad_get_active_agg_info(bond, ad_info); + read_unlock(&bond->lock); + + return ret; +} + int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) { struct slave *slave, *start_at; @@ -2402,8 +2415,8 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) struct ad_info ad_info; int res = 1; - if (bond_3ad_get_active_agg_info(bond, &ad_info)) { - pr_debug("%s: Error: bond_3ad_get_active_agg_info failed\n", + if (__bond_3ad_get_active_agg_info(bond, &ad_info)) { + pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n", dev->name); goto out; } diff --git a/drivers/net/bonding/bond_3ad.h b/drivers/net/bonding/bond_3ad.h index 0cfaa4a..5d91ad0 100644 --- a/drivers/net/bonding/bond_3ad.h +++ b/drivers/net/bonding/bond_3ad.h @@ -273,6 +273,8 @@ void bond_3ad_adapter_speed_changed(struct slave *slave); void bond_3ad_adapter_duplex_changed(struct slave *slave); void bond_3ad_handle_link_change(struct slave *slave, char link); int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info); +int __bond_3ad_get_active_agg_info(struct bonding *bond, + struct ad_info *ad_info); int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev); int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond, struct slave *slave); diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c index 94d06f1..4060d41 100644 --- a/drivers/net/bonding/bond_procfs.c +++ b/drivers/net/bonding/bond_procfs.c @@ -130,7 +130,7 @@ static void bond_info_show_master(struct seq_file *seq) seq_printf(seq, "Aggregator selection policy (ad_select): %s\n", ad_select_tbl[bond->params.ad_select].modename); - if (bond_3ad_get_active_agg_info(bond, &ad_info)) { + if (__bond_3ad_get_active_agg_info(bond, &ad_info)) { seq_printf(seq, "bond %s has no active aggregator\n", bond->dev->name); } else { diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index 77ea237..d7434e0 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -1319,7 +1319,6 @@ static ssize_t bonding_show_mii_status(struct device *d, } static DEVICE_ATTR(mii_status, S_IRUGO, bonding_show_mii_status, NULL); - /* * Show current 802.3ad aggregator ID. */ @@ -1333,7 +1332,7 @@ static ssize_t bonding_show_ad_aggregator(struct device *d, if (bond->params.mode == BOND_MODE_8023AD) { struct ad_info ad_info; count = sprintf(buf, "%d\n", - (bond_3ad_get_active_agg_info(bond, &ad_info)) + bond_3ad_get_active_agg_info(bond, &ad_info) ? 0 : ad_info.aggregator_id); } @@ -1355,7 +1354,7 @@ static ssize_t bonding_show_ad_num_ports(struct device *d, if (bond->params.mode == BOND_MODE_8023AD) { struct ad_info ad_info; count = sprintf(buf, "%d\n", - (bond_3ad_get_active_agg_info(bond, &ad_info)) + bond_3ad_get_active_agg_info(bond, &ad_info) ? 0 : ad_info.ports); } @@ -1377,7 +1376,7 @@ static ssize_t bonding_show_ad_actor_key(struct device *d, if (bond->params.mode == BOND_MODE_8023AD) { struct ad_info ad_info; count = sprintf(buf, "%d\n", - (bond_3ad_get_active_agg_info(bond, &ad_info)) + bond_3ad_get_active_agg_info(bond, &ad_info) ? 0 : ad_info.actor_key); } @@ -1399,7 +1398,7 @@ static ssize_t bonding_show_ad_partner_key(struct device *d, if (bond->params.mode == BOND_MODE_8023AD) { struct ad_info ad_info; count = sprintf(buf, "%d\n", - (bond_3ad_get_active_agg_info(bond, &ad_info)) + bond_3ad_get_active_agg_info(bond, &ad_info) ? 0 : ad_info.partner_key); } -- 2.7.4