[PATCH net] ematch: Fix auto-loading of ematch modules.
flat view
STALE4264d
From: Ignacy Gawędzki <hidden>
Date: 2015-02-16 18:13:42
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
In tcf_em_validate(), when calling tcf_em_lookup(), don't put the resulting pointer directly into em->ops, if the function is to possibly return -EAGAIN after module auto-loading. Otherwise, module_put() will be called by tcf_em_tree_destroy() on em->ops->owner, while it has already been called by tcf_em_validate() before return. Signed-off-by: Ignacy Gawędzki <redacted> --- net/sched/ematch.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/net/sched/ematch.c b/net/sched/ematch.c
index 6742200..39fbe2f 100644
--- a/net/sched/ematch.c
+++ b/net/sched/ematch.c@@ -176,6 +176,7 @@ static int tcf_em_validate(struct tcf_proto *tp, { int err = -EINVAL; struct tcf_ematch_hdr *em_hdr = nla_data(nla); + struct tcf_ematch_ops *em_ops; int data_len = nla_len(nla) - sizeof(*em_hdr); void *data = (void *) em_hdr + sizeof(*em_hdr); struct net *net = dev_net(qdisc_dev(tp->q));
@@ -213,27 +214,29 @@ static int tcf_em_validate(struct tcf_proto *tp, * here. Be aware, the destroy function assumes that the * module is held if the ops field is non zero. */ - em->ops = tcf_em_lookup(em_hdr->kind); + em_ops = tcf_em_lookup(em_hdr->kind); - if (em->ops == NULL) { + if (em_ops == NULL) { err = -ENOENT; #ifdef CONFIG_MODULES __rtnl_unlock(); request_module("ematch-kind-%u", em_hdr->kind); rtnl_lock(); - em->ops = tcf_em_lookup(em_hdr->kind); - if (em->ops) { + em_ops = tcf_em_lookup(em_hdr->kind); + if (em_ops) { /* We dropped the RTNL mutex in order to * perform the module load. Tell the caller * to replay the request. */ - module_put(em->ops->owner); + module_put(em_ops->owner); err = -EAGAIN; } #endif goto errout; } + em->ops = em_ops; + /* ematch module provides expected length of data, so we * can do a basic sanity check. */
--
2.1.0