4.14-stable review patch. If anyone has any objections, please let me know.
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From: Davide Caratti dcaratti@redhat.com
[ Upstream commit 1e46ef1762bb2e52f0f996131a4d16ed4e9fd065 ]
__tcf_ipt_init() can fail after the idr has been successfully reserved. When this happens, subsequent attempts to configure xt/ipt rules using the same idr value systematically fail with -ENOSPC:
# tc action add action xt -j LOG --log-prefix test1 index 100 tablename: mangle hook: NF_IP_POST_ROUTING target: LOG level warning prefix "test1" index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel Command "(null)" is unknown, try "tc actions help". # tc action add action xt -j LOG --log-prefix test1 index 100 tablename: mangle hook: NF_IP_POST_ROUTING target: LOG level warning prefix "test1" index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel Command "(null)" is unknown, try "tc actions help". # tc action add action xt -j LOG --log-prefix test1 index 100 tablename: mangle hook: NF_IP_POST_ROUTING target: LOG level warning prefix "test1" index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel ...
Fix this in the error path of __tcf_ipt_init(), calling tcf_idr_release() in place of tcf_idr_cleanup(). Since tcf_ipt_release() can now be called when tcfi_t is NULL, we also need to protect calls to ipt_destroy_target() to avoid NULL pointer dereference.
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/act_ipt.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/net/sched/act_ipt.c +++ b/net/sched/act_ipt.c @@ -80,9 +80,12 @@ static void ipt_destroy_target(struct xt static void tcf_ipt_release(struct tc_action *a, int bind) { struct tcf_ipt *ipt = to_ipt(a); - ipt_destroy_target(ipt->tcfi_t); + + if (ipt->tcfi_t) { + ipt_destroy_target(ipt->tcfi_t); + kfree(ipt->tcfi_t); + } kfree(ipt->tcfi_tname); - kfree(ipt->tcfi_t); }
static const struct nla_policy ipt_policy[TCA_IPT_MAX + 1] = { @@ -187,7 +190,7 @@ err2: kfree(tname); err1: if (ret == ACT_P_CREATED) - tcf_idr_cleanup(*a, est); + tcf_idr_release(*a, bind); return err; }