Patch "phy: ti: phy-omap-usb2: Fix NULL pointer dereference for SRP" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    phy: ti: phy-omap-usb2: Fix NULL pointer dereference for SRP

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     phy-ti-phy-omap-usb2-fix-null-pointer-dereference-fo.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6606b581e44d0819d2ea60b217201ff6eaf558d4
Author: Tony Lindgren <tony@xxxxxxxxxxx>
Date:   Sun Jan 28 14:05:54 2024 +0200

    phy: ti: phy-omap-usb2: Fix NULL pointer dereference for SRP
    
    [ Upstream commit 7104ba0f1958adb250319e68a15eff89ec4fd36d ]
    
    If the external phy working together with phy-omap-usb2 does not implement
    send_srp(), we may still attempt to call it. This can happen on an idle
    Ethernet gadget triggering a wakeup for example:
    
    configfs-gadget.g1 gadget.0: ECM Suspend
    configfs-gadget.g1 gadget.0: Port suspended. Triggering wakeup
    ...
    Unable to handle kernel NULL pointer dereference at virtual address
    00000000 when execute
    ...
    PC is at 0x0
    LR is at musb_gadget_wakeup+0x1d4/0x254 [musb_hdrc]
    ...
    musb_gadget_wakeup [musb_hdrc] from usb_gadget_wakeup+0x1c/0x3c [udc_core]
    usb_gadget_wakeup [udc_core] from eth_start_xmit+0x3b0/0x3d4 [u_ether]
    eth_start_xmit [u_ether] from dev_hard_start_xmit+0x94/0x24c
    dev_hard_start_xmit from sch_direct_xmit+0x104/0x2e4
    sch_direct_xmit from __dev_queue_xmit+0x334/0xd88
    __dev_queue_xmit from arp_solicit+0xf0/0x268
    arp_solicit from neigh_probe+0x54/0x7c
    neigh_probe from __neigh_event_send+0x22c/0x47c
    __neigh_event_send from neigh_resolve_output+0x14c/0x1c0
    neigh_resolve_output from ip_finish_output2+0x1c8/0x628
    ip_finish_output2 from ip_send_skb+0x40/0xd8
    ip_send_skb from udp_send_skb+0x124/0x340
    udp_send_skb from udp_sendmsg+0x780/0x984
    udp_sendmsg from __sys_sendto+0xd8/0x158
    __sys_sendto from ret_fast_syscall+0x0/0x58
    
    Let's fix the issue by checking for send_srp() and set_vbus() before
    calling them. For USB peripheral only cases these both could be NULL.
    
    Fixes: 657b306a7bdf ("usb: phy: add a new driver for omap usb2 phy")
    Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240128120556.8848-1-tony@xxxxxxxxxxx
    Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
index ca8532a3f193..59d3a692c725 100644
--- a/drivers/phy/ti/phy-omap-usb2.c
+++ b/drivers/phy/ti/phy-omap-usb2.c
@@ -116,7 +116,7 @@ static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
 {
 	struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);
 
-	if (!phy->comparator)
+	if (!phy->comparator || !phy->comparator->set_vbus)
 		return -ENODEV;
 
 	return phy->comparator->set_vbus(phy->comparator, enabled);
@@ -126,7 +126,7 @@ static int omap_usb_start_srp(struct usb_otg *otg)
 {
 	struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);
 
-	if (!phy->comparator)
+	if (!phy->comparator || !phy->comparator->start_srp)
 		return -ENODEV;
 
 	return phy->comparator->start_srp(phy->comparator);