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authorDavide Caratti <dcaratti@redhat.com>2018-03-19 15:31:28 +0100
committerDavid S. Miller <davem@davemloft.net>2018-03-21 18:12:37 -0400
commitf29cdfbe33d6915ba8056179b0041279a67e3647 (patch)
treecc69227adf7745ec621efcc05dd7e50217e21c52
parentd7f20015736048f494988093b59fe513dc232ce9 (diff)
downloadlinux-f29cdfbe33d6915ba8056179b0041279a67e3647.tar.bz2
net/sched: fix idr leak in the error path of tcf_skbmod_init()
tcf_skbmod_init() can fail after the idr has been successfully reserved. When this happens, every subsequent attempt to configure skbmod rules using the same idr value will systematically fail with -ENOSPC, unless the first attempt was done using the 'replace' keyword: # tc action add action skbmod swap mac index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel ... Fix this in tcf_skbmod_init(), ensuring that tcf_idr_release() is called on the error path when the idr has been reserved, but not yet inserted. Also, don't test 'ovr' in the error path, to avoid a 'replace' failure implicitly become a 'delete' that leaks refcount in act_skbmod module: # rmmod act_skbmod; modprobe act_skbmod # tc action add action skbmod swap mac index 100 # tc action add action skbmod swap mac continue index 100 RTNETLINK answers: File exists We have an error talking to the kernel # tc action replace action skbmod swap mac continue index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action list action skbmod # # rmmod act_skbmod rmmod: ERROR: Module act_skbmod is in use Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/act_skbmod.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index d09565d6433e..7b0700f52b50 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -152,7 +152,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
ASSERT_RTNL();
p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL);
if (unlikely(!p)) {
- if (ovr)
+ if (ret == ACT_P_CREATED)
tcf_idr_release(*a, bind);
return -ENOMEM;
}