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authorFlorian Westphal <fw@strlen.de>2022-09-20 19:31:30 +0300
committerFlorian Westphal <fw@strlen.de>2022-09-21 00:50:03 +0300
commitd25088932227680988a6b794221e031a7232f137 (patch)
treebca64dc14c6152bc59d66cf092b67b32c38061e2 /net/netfilter
parent62ce44c4fff947eebdf10bb582267e686e6835c9 (diff)
downloadlinux-d25088932227680988a6b794221e031a7232f137.tar.xz
netfilter: nf_ct_ftp: fix deadlock when nat rewrite is needed
We can't use ct->lock, this is already used by the seqadj internals. When using ftp helper + nat, seqadj will attempt to acquire ct->lock again. Revert back to a global lock for now. Fixes: c783a29c7e59 ("netfilter: nf_ct_ftp: prefer skb_linearize") Reported-by: Bruno de Paula Larini <bruno.larini@riosoft.com.br> Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_conntrack_ftp.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 0d9332e9cf71..617f744a2e3a 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -33,6 +33,7 @@ MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
MODULE_DESCRIPTION("ftp connection tracking helper");
MODULE_ALIAS("ip_conntrack_ftp");
MODULE_ALIAS_NFCT_HELPER(HELPER_NAME);
+static DEFINE_SPINLOCK(nf_ftp_lock);
#define MAX_PORTS 8
static u_int16_t ports[MAX_PORTS];
@@ -409,7 +410,8 @@ static int help(struct sk_buff *skb,
}
datalen = skb->len - dataoff;
- spin_lock_bh(&ct->lock);
+ /* seqadj (nat) uses ct->lock internally, nf_nat_ftp would cause deadlock */
+ spin_lock_bh(&nf_ftp_lock);
fb_ptr = skb->data + dataoff;
ends_in_nl = (fb_ptr[datalen - 1] == '\n');
@@ -538,7 +540,7 @@ out_update_nl:
if (ends_in_nl)
update_nl_seq(ct, seq, ct_ftp_info, dir, skb);
out:
- spin_unlock_bh(&ct->lock);
+ spin_unlock_bh(&nf_ftp_lock);
return ret;
}