CVE-2024-45006

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

xhci: Fix Panther point NULL pointer deref at full-speed re-enumeration

re-enumerating full-speed devices after a failed address device command can trigger a NULL pointer dereference.

Full-speed devices may need to reconfigure the endpoint 0 Max Packet Size value during enumeration. Usb core calls usb_ep0_reinit() in this case, which ends up calling xhci_configure_endpoint().

On Panther point xHC the xhci_configure_endpoint() function will additionally check and reserve bandwidth in software. Other hosts do this in hardware

If xHC address device command fails then a new xhci_virt_device structure is allocated as part of re-enabling the slot, but the bandwidth table pointers are not set up properly here. This triggers the NULL pointer dereference the next time usb_ep0_reinit() is called and xhci_configure_endpoint() tries to check and reserve bandwidth

[46710.713538] usb 3-1: new full-speed USB device number 5 using xhci_hcd [46710.713699] usb 3-1: Device not responding to setup address. [46710.917684] usb 3-1: Device not responding to setup address. [46711.125536] usb 3-1: device not accepting address 5, error -71 [46711.125594] BUG: kernel NULL pointer dereference, address: 0000000000000008 [46711.125600] #PF: supervisor read access in kernel mode [46711.125603] #PF: error_code(0x0000) - not-present page [46711.125606] PGD 0 P4D 0 [46711.125610] Oops: Oops: 0000 [#1] PREEMPT SMP PTI [46711.125615] CPU: 1 PID: 25760 Comm: kworker/1:2 Not tainted 6.10.3_2 #1 [46711.125620] Hardware name: Gigabyte Technology Co., Ltd. [46711.125623] Workqueue: usb_hub_wq hub_event [usbcore] [46711.125668] RIP: 0010:xhci_reserve_bandwidth (drivers/usb/host/xhci.c

Fix this by making sure bandwidth table pointers are set up correctly after a failed address device command, and additionally by avoiding checking for bandwidth in cases like this where no actual endpoints are added or removed, i.e. only context for default control endpoint 0 is evaluated.

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/0f0654318e25b2c185e245ba4a591e42fabb5e59
• https://git.kernel.org/stable/c/365ef7c4277fdd781a695c3553fa157d622d805d
• https://git.kernel.org/stable/c/5ad898ae82412f8a689d59829804bff2999dd0ea
• https://git.kernel.org/stable/c/6b99de301d78e1f5249e57ef2c32e1dec3df2bb1
• https://git.kernel.org/stable/c/8fb9d412ebe2f245f13481e4624b40e651570cbd
• https://git.kernel.org/stable/c/a57b0ebabe6862dce0a2e0f13e17941ad72fc56b
• https://git.kernel.org/stable/c/af8e119f52e9c13e556be9e03f27957554a84656
• https://git.kernel.org/stable/c/ef0a0e616b2789bb804a0ce5e161db03170a85b6