Merge tag 'linux-can-fixes-for-5.10-20201115' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2020-11-15

Anant Thazhemadam contributed two patches for the AF_CAN that prevent potential
access of uninitialized member in can_rcv() and canfd_rcv().

The next patch is by Alejandro Concepcion Rodriguez and changes can_restart()
to use the correct function to push a skb into the networking stack from
process context.

Zhang Qilong's patch fixes a memory leak in the error path of the ti_hecc's
probe function.

A patch by me fixes mcba_usb_start_xmit() function in the mcba_usb driver, to
first fill the skb and then pass it to can_put_echo_skb().

Colin Ian King's patch fixes a potential integer overflow on shift in the
peak_usb driver.

The next two patches target the flexcan driver, a patch by me adds the missing
"req_bit" to the stop mode property comment (which was broken during net-next
for v5.10). Zhang Qilong's patch fixes the failure handling of
pm_runtime_get_sync().

The next seven patches target the m_can driver including the tcan4x5x spi
driver glue code. Enric Balletbo i Serra's patch for the tcan4x5x Kconfig fix
the REGMAP_SPI dependency handling. A patch by me for the tcan4x5x driver's
probe() function adds missing error handling to for devm_regmap_init(), and in
tcan4x5x_can_remove() the order of deregistration is fixed. Wu Bo's patch for
the m_can driver fixes the state change handling in
m_can_handle_state_change(). Two patches by Dan Murphy first introduce
m_can_class_free_dev() and then make use of it to fix the freeing of the can
device. A patch by Faiz Abbas add a missing shutdown of the CAN controller in
the m_can_stop() function.

* tag 'linux-can-fixes-for-5.10-20201115' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: m_can: m_can_stop(): set device to software init mode before closing
  can: m_can: Fix freeing of can device from peripherials
  can: m_can: m_can_class_free_dev(): introduce new function
  can: m_can: m_can_handle_state_change(): fix state change
  can: tcan4x5x: tcan4x5x_can_remove(): fix order of deregistration
  can: tcan4x5x: tcan4x5x_can_probe(): add missing error checking for devm_regmap_init()
  can: tcan4x5x: replace depends on REGMAP_SPI with depends on SPI
  can: flexcan: fix failure handling of pm_runtime_get_sync()
  can: flexcan: flexcan_setup_stop_mode(): add missing "req_bit" to stop mode property comment
  can: peak_usb: fix potential integer overflow on shift of a int
  can: mcba_usb: mcba_usb_start_xmit(): first fill skb, then pass to can_put_echo_skb()
  can: ti_hecc: Fix memleak in ti_hecc_probe
  can: dev: can_restart(): post buffer from the right context
  can: af_can: prevent potential access of uninitialized member in canfd_rcv()
  can: af_can: prevent potential access of uninitialized member in can_rcv()
====================

Link: https://lore.kernel.org/r/20201115174131.2089251-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 28 insertions, 10 deletions

diff --git a/net/can/af_can.c b/net/can/af_can.c
index 6373ab9c5507..5d124c155904 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -677,16 +677,25 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
 {
 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 
-	if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU ||
-		     cfd->len > CAN_MAX_DLEN)) {
-		pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
+	if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) {
+		pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
+			     dev->type, skb->len);
+		goto free_skb;
+	}
+
+	/* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
+	if (unlikely(cfd->len > CAN_MAX_DLEN)) {
+		pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n",
 			     dev->type, skb->len, cfd->len);
-		kfree_skb(skb);
-		return NET_RX_DROP;
+		goto free_skb;
 	}
 
 	can_receive(skb, dev);
 	return NET_RX_SUCCESS;
+
+free_skb:
+	kfree_skb(skb);
+	return NET_RX_DROP;
 }
 
 static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
@@ -694,16 +703,25 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
 {
 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 
-	if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU ||
-		     cfd->len > CANFD_MAX_DLEN)) {
-		pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n",
+	if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) {
+		pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
+			     dev->type, skb->len);
+		goto free_skb;
+	}
+
+	/* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
+	if (unlikely(cfd->len > CANFD_MAX_DLEN)) {
+		pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n",
 			     dev->type, skb->len, cfd->len);
-		kfree_skb(skb);
-		return NET_RX_DROP;
+		goto free_skb;
 	}
 
 	can_receive(skb, dev);
 	return NET_RX_SUCCESS;
+
+free_skb:
+	kfree_skb(skb);
+	return NET_RX_DROP;
 }
 
 /* af_can protocol functions */