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| author | Davide Caratti <dcaratti@redhat.com> | 2018-03-19 15:31:28 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-21 18:12:37 -0400 |
| commit | f29cdfbe33d6915ba8056179b0041279a67e3647 (patch) | |
| tree | cc69227adf7745ec621efcc05dd7e50217e21c52 /net | |
| parent | d7f20015736048f494988093b59fe513dc232ce9 (diff) | |
| download | linux-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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/act_skbmod.c | 2 |
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; } |