[PATCH net] net/sched: em_canid: add length check before reading CAN ID
From: <hidden>
Date: 2025-11-26 03:46:12
Also in:
linux-can, linux-kernel-mentees, lkml
Subsystem:
can network layer, networking [general], tc subsystem, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Shaurya Rane <redacted> Add a check to verify that the skb has at least sizeof(canid_t) bytes before reading the CAN ID from skb->data. This prevents reading uninitialized memory when processing malformed packets that don't contain a valid CAN frame. Reported-by: syzbot+5d8269a1e099279152bc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=5d8269a1e099279152bc Fixes: f057bbb6f9ed ("net: em_canid: Ematch rule to match CAN frames according to their identifiers") Signed-off-by: Shaurya Rane <redacted> --- net/sched/em_canid.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/sched/em_canid.c b/net/sched/em_canid.c
index 5337bc462755..a9b6cab70ff1 100644
--- a/net/sched/em_canid.c
+++ b/net/sched/em_canid.c@@ -99,6 +99,9 @@ static int em_canid_match(struct sk_buff *skb, struct tcf_ematch *m, int i; const struct can_filter *lp; + if (skb->len < sizeof(canid_t)) + return 0; + can_id = em_canid_get_id(skb); if (can_id & CAN_EFF_FLAG) {
--
2.34.1