From: Oleksij Rempel o.rempel@pengutronix.de
mainline inclusion from mainline-v5.9-rc2 commit 840835c9281215341d84966a8855f267a971e6a3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4CE CVE: CVE-2021-47232
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Sometimes it makes no sense to search the skb by pkt.dpo, since we need next the skb within the transaction block. This may happen if we have an ETP session with CTS set to less than 255 packets.
After this patch, we will be able to work with ETP sessions where the block size (ETP.CM_CTS byte 2) is less than 255 packets.
Reported-by: Henrique Figueira henrislip@gmail.com Reported-by: https://github.com/linux-can/can-utils/issues/228 Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Oleksij Rempel o.rempel@pengutronix.de Link: https://lore.kernel.org/r/20200807105200.26441-5-o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Zhang Changzhong zhangchangzhong@huawei.com --- net/can/j1939/transport.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 9f99af5..3320d70 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -352,17 +352,16 @@ void j1939_session_skb_queue(struct j1939_session *session, skb_queue_tail(&session->skb_queue, skb); }
-static struct sk_buff *j1939_session_skb_find(struct j1939_session *session) +static struct +sk_buff *j1939_session_skb_find_by_offset(struct j1939_session *session, + unsigned int offset_start) { struct j1939_priv *priv = session->priv; + struct j1939_sk_buff_cb *do_skcb; struct sk_buff *skb = NULL; struct sk_buff *do_skb; - struct j1939_sk_buff_cb *do_skcb; - unsigned int offset_start; unsigned long flags;
- offset_start = session->pkt.dpo * 7; - spin_lock_irqsave(&session->skb_queue.lock, flags); skb_queue_walk(&session->skb_queue, do_skb) { do_skcb = j1939_skb_to_cb(do_skb); @@ -382,6 +381,14 @@ static struct sk_buff *j1939_session_skb_find(struct j1939_session *session) return skb; }
+static struct sk_buff *j1939_session_skb_find(struct j1939_session *session) +{ + unsigned int offset_start; + + offset_start = session->pkt.dpo * 7; + return j1939_session_skb_find_by_offset(session, offset_start); +} + /* see if we are receiver * returns 0 for broadcasts, although we will receive them */ @@ -766,7 +773,7 @@ static int j1939_session_tx_dat(struct j1939_session *session) int ret = 0; u8 dat[8];
- se_skb = j1939_session_skb_find(session); + se_skb = j1939_session_skb_find_by_offset(session, session->pkt.tx * 7); if (!se_skb) return -ENOBUFS;
@@ -1750,7 +1757,8 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session, __func__, session); goto out_session_cancel; } - se_skb = j1939_session_skb_find(session); + + se_skb = j1939_session_skb_find_by_offset(session, packet * 7); if (!se_skb) { netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__, session);