From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 1/9] netfilter: nf_ct_h323: do not re-activate already expired timer
Date: Wed, 10 Aug 2016 21:16:37 +0200 [thread overview]
Message-ID: <1470856605-7903-2-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1470856605-7903-1-git-send-email-pablo@netfilter.org>
From: Liping Zhang <liping.zhang@spreadtrum.com>
Commit 96d1327ac2e3 ("netfilter: h323: Use mod_timer instead of
set_expect_timeout") just simplify the source codes
if (!del_timer(&exp->timeout))
return 0;
add_timer(&exp->timeout);
to mod_timer(&exp->timeout, jiffies + info->timeout * HZ);
This is not correct, and introduce a race codition:
CPU0 CPU1
- timer expire
process_rcf expectation_timed_out
lock(exp_lock) -
find_exp waiting exp_lock...
re-activate timer!! waiting exp_lock...
unlock(exp_lock) lock(exp_lock)
- unlink expect
- free(expect)
- unlock(exp_lock)
So when the timer expires again, we will access the memory that
was already freed.
Replace mod_timer with mod_timer_pending here to fix this problem.
Fixes: 96d1327ac2e3 ("netfilter: h323: Use mod_timer instead of set_expect_timeout")
Cc: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_conntrack_h323_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index bb77a97..5c0db5c 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -1473,7 +1473,8 @@ static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
"timeout to %u seconds for",
info->timeout);
nf_ct_dump_tuple(&exp->tuple);
- mod_timer(&exp->timeout, jiffies + info->timeout * HZ);
+ mod_timer_pending(&exp->timeout,
+ jiffies + info->timeout * HZ);
}
spin_unlock_bh(&nf_conntrack_expect_lock);
}
--
2.1.4
next prev parent reply other threads:[~2016-08-10 19:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-10 19:16 [PATCH 0/9] Netfilter fixes for net Pablo Neira Ayuso
2016-08-10 19:16 ` Pablo Neira Ayuso [this message]
2016-08-10 19:16 ` [PATCH 2/9] netfilter: nf_tables: s/MFT_REG32_01/NFT_REG32_01 Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 3/9] netfilter: nft_rbtree: ignore inactive matching element with no descendants Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 4/9] netfilter: nf_conntrack_sip: CSeq 0 is a valid CSeq Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 5/9] netfilter: nf_ct_expect: remove the redundant slash when policy name is empty Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 6/9] netfilter: nfnetlink_queue: fix memory leak when attach expectation successfully Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 7/9] netfilter: nfnetlink_queue: reject verdict request from different portid Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 8/9] netfilter: ctnetlink: reject new conntrack request with different l4proto Pablo Neira Ayuso
2016-08-10 19:16 ` [PATCH 9/9] netfilter: nft_exthdr: Add size check on u8 nft_exthdr attributes Pablo Neira Ayuso
-- strict thread matches above, loose matches on Subject: below --
2016-08-10 18:56 [PATCH 0/9] Netfilter fixes for net Pablo Neira Ayuso
2016-08-10 18:56 ` [PATCH 1/9] netfilter: nf_ct_h323: do not re-activate already expired timer Pablo Neira Ayuso
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1470856605-7903-2-git-send-email-pablo@netfilter.org \
--to=pablo@netfilter.org \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).