hso_free_net_device in drivers/net/usb/hso.c in the Linux kernel through 5.13.4 calls unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-37159
• https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
• https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
• https://www.spinics.net/lists/linux-usb/msg202228.html
• https://www.oracle.com/security-alerts/cpujul2022.html
• https://bugzilla.suse.com/show_bug.cgi?id=1188601
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a6ecfb39ba9d7316057cea823b196b734f6b18ca
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=dcb713d53e2eadf42b878c12a471e74dc6ed3145
• https://security.netapp.com/advisory/ntap-20210819-0003