DigiGoon/android_kernel_xiaomi_sm8350
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Revert "genetlink: hold RCU in genlmsg_mcast()"

Browse source 
This reverts commit 0d2bd44bfe which is
commit 56440d7ec28d60f8da3bfa09062b3368ff9b16db upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ie8c829833eef0ab6b68677f3da08620e894787a0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2024-11-09 16:39:38 +00:00
parent 9d6ed89ef0
commit bc1dcc543b
5 changed files with 25 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/target/target_core_user.c
View file

@ -1788,7 +1788,7 @@ static int tcmu_netlink_event_send(struct tcmu_dev *udev,
}
ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
TCMU_MCGRP_CONFIG);
TCMU_MCGRP_CONFIG, GFP_KERNEL);
/* Wait during an add as the listener may not be up yet */
if (ret == 0 ||

3
include/net/genetlink.h
View file

@ -296,12 +296,13 @@ static inline int genlmsg_multicast(const struct genl_family *family,
* @skb: netlink message as socket buffer
* @portid: own netlink portid to avoid sending to yourself
* @group: offset of multicast group in groups array
* @flags: allocation flags
*
* This function must hold the RTNL or rcu_read_lock().
*/
int genlmsg_multicast_allns(const struct genl_family *family,
struct sk_buff *skb, u32 portid,
unsigned int group);
unsigned int group, gfp_t flags);
/**
* genlmsg_unicast - unicast a netlink message

4
net/l2tp/l2tp_netlink.c
View file

@ -117,7 +117,7 @@ static int l2tp_tunnel_notify(struct genl_family *family,
NLM_F_ACK, tunnel, cmd);
if (ret >= 0) {
ret = genlmsg_multicast_allns(family, msg, 0, 0);
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;
@ -145,7 +145,7 @@ static int l2tp_session_notify(struct genl_family *family,
NLM_F_ACK, session, cmd);
if (ret >= 0) {
ret = genlmsg_multicast_allns(family, msg, 0, 0);
ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
/* We don't care if no one is listening */
if (ret == -ESRCH)
ret = 0;

28
net/netlink/genetlink.c
View file

@ -949,11 +949,15 @@ static int genl_ctrl_event(int event, const struct genl_family *family,
if (IS_ERR(msg))
return PTR_ERR(msg);
if (!family->netnsok)
if (!family->netnsok) {
genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
0, GFP_KERNEL);
else
genlmsg_multicast_allns(&genl_ctrl, msg, 0, 0);
} else {
rcu_read_lock();
genlmsg_multicast_allns(&genl_ctrl, msg, 0,
0, GFP_ATOMIC);
rcu_read_unlock();
}
return 0;
}
@ -1054,23 +1058,23 @@ struct nlattr **genl_family_attrbuf(const struct genl_family *family)
}
EXPORT_SYMBOL(genl_family_attrbuf);
static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group)
static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
gfp_t flags)
{
struct sk_buff *tmp;
struct net *net, *prev = NULL;
bool delivered = false;
int err;
rcu_read_lock();
for_each_net_rcu(net) {
if (prev) {
tmp = skb_clone(skb, GFP_ATOMIC);
tmp = skb_clone(skb, flags);
if (!tmp) {
err = -ENOMEM;
goto error;
}
err = nlmsg_multicast(prev->genl_sock, tmp,
portid, group, GFP_ATOMIC);
portid, group, flags);
if (!err)
delivered = true;
else if (err != -ESRCH)
@ -1079,30 +1083,26 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group)
prev = net;
}
err = nlmsg_multicast(prev->genl_sock, skb, portid, group, GFP_ATOMIC);
rcu_read_unlock();
err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
if (!err)
delivered = true;
else if (err != -ESRCH)
return err;
return delivered ? 0 : -ESRCH;
error:
rcu_read_unlock();
kfree_skb(skb);
return err;
}
int genlmsg_multicast_allns(const struct genl_family *family,
struct sk_buff *skb, u32 portid,
unsigned int group)
unsigned int group, gfp_t flags)
{
if (WARN_ON_ONCE(group >= family->n_mcgrps))
return -EINVAL;
group = family->mcgrp_offset + group;
return genlmsg_mcast(skb, portid, group);
return genlmsg_mcast(skb, portid, group, flags);
}
EXPORT_SYMBOL(genlmsg_multicast_allns);

8
net/wireless/nl80211.c
View file

@ -15407,8 +15407,10 @@ void nl80211_common_reg_change_event(enum nl80211_commands cmd_id,
genlmsg_end(msg, hdr);
rcu_read_lock();
genlmsg_multicast_allns(&nl80211_fam, msg, 0,
NL80211_MCGRP_REGULATORY);
NL80211_MCGRP_REGULATORY, GFP_ATOMIC);
rcu_read_unlock();
return;
@ -15907,8 +15909,10 @@ void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
genlmsg_end(msg, hdr);
rcu_read_lock();
genlmsg_multicast_allns(&nl80211_fam, msg, 0,
NL80211_MCGRP_REGULATORY);
NL80211_MCGRP_REGULATORY, GFP_ATOMIC);
rcu_read_unlock();
return;