From: Fedor Pchelkin <pchelkin@xxxxxxxxx>
commit 8ef49f7f8244424adcf4a546dba4cbbeb0b09c09 upstream.
We should warn user-space that it is doing something wrong when trying
to activate sessions with identical parameters but WARN_ON_ONCE macro
can not be used here as it serves a different purpose.
So it would be good to replace it with netdev_warn_once() message.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20220729143655.1108297-1-pchelkin@xxxxxxxxx
[mkl: fix indention]
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/can/j1939/socket.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -178,7 +178,10 @@ activate_next:
if (!first)
return;
- if (WARN_ON_ONCE(j1939_session_activate(first))) {
+ if (j1939_session_activate(first)) {
+ netdev_warn_once(first->priv->ndev,
+ "%s: 0x%p: Identical session is already activated.\n",
+ __func__, first);
first->err = -EBUSY;
goto activate_next;
} else {
