CVE-2024-26600

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

Lets fix the issue by checking for send_srp() and set_vbus() before calling them. For USB peripheral only cases these both could be NULL.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/0430bfcd46657d9116a26cd377f112cbc40826a4
• https://git.kernel.org/stable/c/14ef61594a5a286ae0d493b8acbf9eac46fd04c4
• https://git.kernel.org/stable/c/396e17af6761b3cc9e6e4ca94b4de7f642bfece1
• https://git.kernel.org/stable/c/486218c11e8d1c8f515a3bdd70d62203609d4b6b
• https://git.kernel.org/stable/c/7104ba0f1958adb250319e68a15eff89ec4fd36d
• https://git.kernel.org/stable/c/8398d8d735ee93a04fb9e9f490e8cacd737e3bf5
• https://git.kernel.org/stable/c/8cc889b9dea0579726be9520fcc766077890b462
• https://git.kernel.org/stable/c/be3b82e4871ba00e9b5d0ede92d396d579d7b3b3
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html