diff options
| author | Shaurya Rane <ssrane_b23@ee.vjti.ac.in> | 2025-11-26 14:27:18 +0530 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2025-11-26 16:28:10 +0100 |
| commit | 0c922106d7a58d106c6a5c52a741ae101cfaf088 (patch) | |
| tree | 6e6279bb8bcb7e465c2c516878a81cf15c3d6c81 | |
| parent | 6d849ff573722afcf5508d2800017bdd40f27eb9 (diff) | |
net/sched: em_canid: fix uninit-value in em_canid_match
Use pskb_may_pull() to ensure a complete CAN frame is present in the
linear data buffer before reading the CAN ID. A simple skb->len check
is insufficient because it only verifies the total data length but does
not guarantee the data is present in skb->data (it could be in
fragments).
pskb_may_pull() both validates the length and pulls fragmented data
into the linear buffer if necessary, making it safe to directly
access skb->data.
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 <ssrane_b23@ee.vjti.ac.in>
Link: https://patch.msgid.link/20251126085718.50808-1-ssranevjti@gmail.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | net/sched/em_canid.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/sched/em_canid.c b/net/sched/em_canid.c index 5337bc462755..2d27f91d8441 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 (!pskb_may_pull(skb, CAN_MTU)) + return 0; + can_id = em_canid_get_id(skb); if (can_id & CAN_EFF_FLAG) { |