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| author |   Vasily Averin <vvs@virtuozzo.com> | 2021-07-01 08:02:49 +0300 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2021-07-02 02:29:20 +0200 |
| commit | c23a9fd209bc6f8c1fa6ee303fdf037d784a1627 (patch) | |
| tree | 5d9b8538a7fa688a583fb1d40167e3decf52663b /net/netfilter/nf_conntrack_netlink.c | |
| parent | netfilter: conntrack: nf_ct_gre_keymap_flush() removal (diff) | |
| download | linux-dev-c23a9fd209bc6f8c1fa6ee303fdf037d784a1627.tar.xz linux-dev-c23a9fd209bc6f8c1fa6ee303fdf037d784a1627.zip | |
netfilter: ctnetlink: suspicious RCU usage in ctnetlink_dump_helpinfo
Two patches listed below removed ctnetlink_dump_helpinfo call from under
rcu_read_lock. Now its rcu_dereference generates following warning:
=============================
WARNING: suspicious RCU usage
5.13.0+ #5 Not tainted
-----------------------------
net/netfilter/nf_conntrack_netlink.c:221 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
stack backtrace:
CPU: 1 PID: 2251 Comm: conntrack Not tainted 5.13.0+ #5
Call Trace:
dump_stack+0x7f/0xa1
ctnetlink_dump_helpinfo+0x134/0x150 [nf_conntrack_netlink]
ctnetlink_fill_info+0x2c2/0x390 [nf_conntrack_netlink]
ctnetlink_dump_table+0x13f/0x370 [nf_conntrack_netlink]
netlink_dump+0x10c/0x370
__netlink_dump_start+0x1a7/0x260
ctnetlink_get_conntrack+0x1e5/0x250 [nf_conntrack_netlink]
nfnetlink_rcv_msg+0x613/0x993 [nfnetlink]
netlink_rcv_skb+0x50/0x100
nfnetlink_rcv+0x55/0x120 [nfnetlink]
netlink_unicast+0x181/0x260
netlink_sendmsg+0x23f/0x460
sock_sendmsg+0x5b/0x60
__sys_sendto+0xf1/0x160
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x36/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixes: 49ca022bccc5 ("netfilter: ctnetlink: don't dump ct extensions of unconfirmed conntracks")
Fixes: 0b35f6031a00 ("netfilter: Remove duplicated rcu_read_lock.")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_conntrack_netlink.c')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 4e1a9dba7077..e81af33b233b 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -218,6 +218,7 @@ static int ctnetlink_dump_helpinfo(struct sk_buff *skb, if (!help) return 0; + rcu_read_lock(); helper = rcu_dereference(help->helper); if (!helper) goto out; @@ -233,9 +234,11 @@ static int ctnetlink_dump_helpinfo(struct sk_buff *skb, nla_nest_end(skb, nest_helper); out: + rcu_read_unlock(); return 0; nla_put_failure: + rcu_read_unlock(); return -1; } |