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authorGao Feng <gfree.wind@vip.163.com>2017-06-28 12:53:54 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-21 07:42:17 +0200
commitdc491cdd2c81588ca6110f07325e32535192bcf0 (patch)
tree9df83d2f2172866a59d72860f29ee24a94ba0b44 /net/sched
parent13550ffc9515d234c43d79ef4a87328e88182baa (diff)
net: sched: Fix one possible panic when no destroy callback
commit c1a4872ebfb83b1af7144f7b29ac8c4b344a12a8 upstream. When qdisc fail to init, qdisc_create would invoke the destroy callback to cleanup. But there is no check if the callback exists really. So it would cause the panic if there is no real destroy callback like the qdisc codel, fq, and so on. Take codel as an example following: When a malicious user constructs one invalid netlink msg, it would cause codel_init->codel_change->nla_parse_nested failed. Then kernel would invoke the destroy callback directly but qdisc codel doesn't define one. It causes one panic as a result. Now add one the check for destroy to avoid the possible panic. Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Signed-off-by: Gao Feng <gfree.wind@vip.163.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_api.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 4bc7a3b64478..ff27a85a71a9 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1009,7 +1009,8 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
return sch;
}
/* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
- ops->destroy(sch);
+ if (ops->destroy)
+ ops->destroy(sch);
err_out3:
dev_put(dev);
kfree((char *) sch - sch->padded);