From c35636e91e392e1540949bbc67932167cb48bc3a Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Wed, 18 Feb 2026 11:58:06 +0100 Subject: [PATCH] can: bcm: fix locking for bcm_op runtime updates Commit c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates") added a locking for some variables that can be modified at runtime when updating the sending bcm_op with a new TX_SETUP command in bcm_tx_setup(). Usually the RX_SETUP only handles and filters incoming traffic with one exception: When the RX_RTR_FRAME flag is set a predefined CAN frame is sent when a specific RTR frame is received. Therefore the rx bcm_op uses bcm_can_tx() which uses the bcm_tx_lock that was only initialized in bcm_tx_setup(). Add the missing spin_lock_init() when allocating the bcm_op in bcm_rx_setup() to handle the RTR case properly. Fixes: c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates") Reported-by: syzbot+5b11eccc403dd1cea9f8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-can/699466e4.a70a0220.2c38d7.00ff.GAE@google.com/ Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260218-bcm_spin_lock_init-v1-1-592634c8a5b5@hartkopp.net Signed-off-by: Marc Kleine-Budde --- net/can/bcm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/can/bcm.c b/net/can/bcm.c index b7324e9c955b..fd9fa072881e 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -1176,6 +1176,7 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, if (!op) return -ENOMEM; + spin_lock_init(&op->bcm_tx_lock); op->can_id = msg_head->can_id; op->nframes = msg_head->nframes; op->cfsiz = CFSIZ(msg_head->flags);