From: Davide Caratti Date: Mon, 19 Mar 2018 14:31:27 +0000 (+0100) Subject: net/sched: fix idr leak in the error path of tcf_vlan_init() X-Git-Tag: v5.15~9226^2~12^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d7f20015736048f494988093b59fe513dc232ce9;p=platform%2Fkernel%2Flinux-starfive.git net/sched: fix idr leak in the error path of tcf_vlan_init() tcf_vlan_init() can fail after the idr has been successfully reserved. When this happens, every subsequent attempt to configure vlan 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 vlan pop index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action add action vlan pop index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel # tc action add action vlan pop index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel ... Fix this in tcf_vlan_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_vlan module: # rmmod act_vlan; modprobe act_vlan # tc action add action vlan push id 5 index 100 # tc action replace action vlan push id 7 index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action list action vlan # # rmmod act_vlan rmmod: ERROR: Module act_vlan is in use Fixes: 4c5b9d9642c8 ("act_vlan: VLAN action rewrite to use RCU lock/unlock and update") Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Acked-by: Jamal Hadi Salim Signed-off-by: Davide Caratti Signed-off-by: David S. Miller --- diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c index c2914e9..c49cb61 100644 --- a/net/sched/act_vlan.c +++ b/net/sched/act_vlan.c @@ -195,7 +195,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, ASSERT_RTNL(); p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) { - if (ovr) + if (ret == ACT_P_CREATED) tcf_idr_release(*a, bind); return -ENOMEM; }