CVE-2024-46760

What the bug is

Right now it's possible to hit NULL pointer dereference in rtw_rx_fill_rx_status on hw object and/or its fields because initialization routine can start getting USB replies before rtw_dev is fully setup. The stack trace looks like this: rtw_rx_fill_rx_status rtw8821c_query_rx_desc rtw_usb_rx_handler ... queue_work rtw_usb_read_port_complete ... usb_submit_urb rtw_usb_rx_resubmit rtw_usb_init_rx rtw_usb_probe So while we do the async stuff rtw_usb_probe continues and calls rtw_register_hw, which does all kinds of initialization (e.g. via ieee80211_register_hw) that rtw_rx_fill_rx_status relies on. Fix this by moving the first usb_submit_urb after everything is set up. For me, this bug manifested as: [ 8.893177] rtw_8821cu 1-1:1.2: band wrong, packet dropped [ 8.910904] rtw_8821cu 1-1:1.2: hw->conf.chandef.chan NULL in rtw_rx_fill_rx_status because I'm using Larry's backport of rtw88 driver with the NULL checks in rtw_rx_fill_rx_status.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/net/wireless/realtek/rtw88/usb.c

What this is

REALTEK WIRELESS DRIVER (rtw88)MAINTAINERS section matched on drivers/net/wireless/realtek/rtw88/ · linux-wireless@vger.kernel.org · Maintained

Kernel module

rtw88_usb

Check it on the machine

grep -wE 'CONFIG_RTW88|CONFIG_RTW88_USB|CONFIG_WLAN|CONFIG_WLAN_VENDOR_REALTEK' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w rtw88_usb

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed. The build rule could not be established for 1 release, so nothing is claimed about those.

• bookworm?
• trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x

?

not established - no Makefile entry for the affected file

M

a module where it is built at all; some flavours do not build it

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_RTW88, CONFIG_RTW88_USB, CONFIG_WLAN, CONFIG_WLAN_VENDOR_REALTEK

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2024-09-18 (2 years ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.23%, higher than 13.3% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
5.2	6.6.51	c83d464b82a8
5.2	6.10.10	25eaef533bf3
5.2	6.11	adc539784c98