* [PATCH] net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak
@ 2026-03-28 21:14 Yochai Eisenrich
0 siblings, 0 replies; only message in thread
From: Yochai Eisenrich @ 2026-03-28 21:14 UTC (permalink / raw)
To: David S . Miller
Cc: Yochai Eisenrich, Jamal Hadi Salim, Jiri Pirko, security, netdev
When building netlink messages, tc_chain_fill_node() never initializes
the tcm_info field of struct tcmsg. Since the allocation is not zeroed,
kernel heap memory is leaked to userspace through this 4-byte field.
The fix simply zeroes tcm_info alongside the other fields that are
already initialized.
Fixes: 32a4f5ecd738 ("net: sched: introduce chain object to uapi")
Signed-off-by: Yochai Eisenrich <echelonh@gmail.com>
---
net/sched/cls_api.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 4829c27446e3..20f7f9ee0b35 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2969,6 +2969,7 @@ static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
tcm->tcm__pad1 = 0;
tcm->tcm__pad2 = 0;
tcm->tcm_handle = 0;
+ tcm->tcm_info = 0;
if (block->q) {
tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
tcm->tcm_parent = block->q->handle;
--
2.53.0
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2026-03-28 21:14 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-28 21:14 [PATCH] net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak Yochai Eisenrich
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox