4.14-stable review patch. If anyone has any objections, please let me know.
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From: Roman Mashak mrv@mojatatu.com
[ Upstream commit a52956dfc503f8cc5cfe6454959b7049fddb4413 ]
When application fails to pass flags in netlink TLV when replacing existing skbmod action, the kernel will leak refcnt:
$ tc actions get action skbmod index 1 total acts 0
action order 0: skbmod pipe set smac 00:11:22:33:44:55 index 1 ref 1 bind 0
For example, at this point a buggy application replaces the action with index 1 with new smac 00:aa:22:33:44:55, it fails because of zero flags, however refcnt gets bumped:
$ tc actions get actions skbmod index 1 total acts 0
action order 0: skbmod pipe set smac 00:11:22:33:44:55 index 1 ref 2 bind 0 $
Tha patch fixes this by calling tcf_idr_release() on existing actions.
Fixes: 86da71b57383d ("net_sched: Introduce skbmod action") Signed-off-by: Roman Mashak mrv@mojatatu.com Acked-by: Cong Wang xiyou.wangcong@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/act_skbmod.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -131,8 +131,11 @@ static int tcf_skbmod_init(struct net *n if (exists && bind) return 0;
- if (!lflags) + if (!lflags) { + if (exists) + tcf_idr_release(*a, bind); return -EINVAL; + }
if (!exists) { ret = tcf_idr_create(tn, parm->index, est, a,