In the Linux kernel, the following vulnerability has been resolved:

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

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.

Linux https://git.kernel.org/stable/c/0430bfcd46657d9116a26cd377f112cbc40826a4 [No types assigned]

Linux https://git.kernel.org/stable/c/14ef61594a5a286ae0d493b8acbf9eac46fd04c4 [No types assigned]

Linux https://git.kernel.org/stable/c/396e17af6761b3cc9e6e4ca94b4de7f642bfece1 [No types assigned]

Linux https://git.kernel.org/stable/c/486218c11e8d1c8f515a3bdd70d62203609d4b6b [No types assigned]

Linux https://git.kernel.org/stable/c/7104ba0f1958adb250319e68a15eff89ec4fd36d [No types assigned]

Linux https://git.kernel.org/stable/c/8398d8d735ee93a04fb9e9f490e8cacd737e3bf5 [No types assigned]

Linux https://git.kernel.org/stable/c/8cc889b9dea0579726be9520fcc766077890b462 [No types assigned]

Linux https://git.kernel.org/stable/c/be3b82e4871ba00e9b5d0ede92d396d579d7b3b3 [No types assigned]