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authorMark Huang <mlhuang@cs.princeton.edu>2006-08-13 18:57:54 -0700
committerDavid S. Miller <davem@davemloft.net>2006-08-13 18:57:54 -0700
commitdcb7cd97f133f7cfbd181149a1e60215a869f895 (patch)
tree73e600aa19051981a566ad55ca5fa6f9acec4f7a
parent0eff66e625306a794ecba4b29ed12f7a147ce219 (diff)
[NETFILTER]: ulog: fix panic on SMP kernels
Fix kernel panic on various SMP machines. The culprit is a null ub->skb in ulog_send(). If ulog_timer() has already been scheduled on one CPU and is spinning on the lock, and ipt_ulog_packet() flushes the queue on another CPU by calling ulog_send() right before it exits, there will be no skbuff when ulog_timer() acquires the lock and calls ulog_send(). Cancelling the timer in ulog_send() doesn't help because it has already been scheduled and is running on the first CPU. Similar problem exists in ebt_ulog.c and nfnetlink_log.c. Signed-off-by: Mark Huang <mlhuang@cs.princeton.edu> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/bridge/netfilter/ebt_ulog.c3
-rw-r--r--net/ipv4/netfilter/ipt_ULOG.c5
-rw-r--r--net/netfilter/nfnetlink_log.c3
3 files changed, 11 insertions, 0 deletions
diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c
index 02693a230dc1..9f950db3b76f 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -74,6 +74,9 @@ static void ulog_send(unsigned int nlgroup)
if (timer_pending(&ub->timer))
del_timer(&ub->timer);
+ if (!ub->skb)
+ return;
+
/* last nlmsg needs NLMSG_DONE */
if (ub->qlen > 1)
ub->lastnlh->nlmsg_type = NLMSG_DONE;
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index d7dd7fe7051c..d46fd677fa11 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -115,6 +115,11 @@ static void ulog_send(unsigned int nlgroupnum)
del_timer(&ub->timer);
}
+ if (!ub->skb) {
+ DEBUGP("ipt_ULOG: ulog_send: nothing to send\n");
+ return;
+ }
+
/* last nlmsg needs NLMSG_DONE */
if (ub->qlen > 1)
ub->lastnlh->nlmsg_type = NLMSG_DONE;
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 61cdda4e5d3b..b59d3b2bde21 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -366,6 +366,9 @@ __nfulnl_send(struct nfulnl_instance *inst)
if (timer_pending(&inst->timer))
del_timer(&inst->timer);
+ if (!inst->skb)
+ return 0;
+
if (inst->qlen > 1)
inst->lastnlh->nlmsg_type = NLMSG_DONE;